I first encountered this phenonmenon with the movie True Lies. I was around 16 when I saw it, and watched the first fifteen or twenty minutes through a standard action movie with amusing sidekick moments filter. Thus I was a bit perplexed by Charlton Heston's over the top, eyepatched spy boss character. However, once Ahnold chases (on horseback) the Big Bad (on a motorcycle) up to the roof of a building, I was beginning to suspect that there was an eye wink I had missed. Then when the Governator tries to get his horse to jump from one rooftop to the next in pursuit of the badguy, I finally got the joke. True Lies is no standard action movie with big stunts and crazy special effects. It's a satire of same, designed specifically to show the rediculousness of the genre. I started paying attention to the feedback of the movie and realized that critics bemoaning the film's lack of believability so did not Get It.
Looking back on that experience, I realized that the first tell that the movie is satire can be found in the title: True Lies. The second was the parenthetical "perfect Arabic" in the subtitle explaining Arnold had escaped a guard's attention by claiming to be lost while desperately seeking a Water Closet. I was young, though, and not accustomed to a big-budget product being something other than its obvious packaging. But I was hooked on this concept ever since watching that movie, particularly when it comes to satirizing action movies, a mainstream flogging of the Gary Stu phenomenon that puts even the most inane self-insertion fanfiction to shame. (Don't get me started on the Jack Ryan movies, let alone the books.)
Some movies are going to be obvious, moving from satire into baldfaced parody (see all the Austin Powers movies). Some will, like True Lies provide early tells but front as the Real Deal. Finding those first few tells is vital (for Shoot 'Em Up, it was the protagonist killing a bad guy with a carrot to the jugular; for Wanted, it was the fact that a society of weavers--no shit, weavers--had formed a fraternity of assassins) for the best experience of the movie or book.
Then there are a subset of books and movies that are so exaggerated that you think it must be satire, that you've found tell after tell--only to realize that it's likely meant in all seriousness. For example, I'm still unsure about Independence Day as action satire because there are just enough moments in which the movie takes itself seriously to confuse the issue. Sometimes, over the course of a first exposure, you can determine without a doubt that you are not reading satire but Serious Genre Fiction. This was my experience with Ghost by John Ringo. I went into that book not knowing anything about the author or his previous books. I laughed my way through the first third of the first act, thinking it was superb satire to the pain of parody at points of a particular mindset. But when all the other characters played straight-faced along with the protagonist's thinking, I realized I wasn't reading satire, and I stopped laughing. (But I kept reading, mostly due to a "deer-in-headlights" way. See this review for more on this topic.)
On-line essays are a real bear in the satire navigation department. With a book or a movie, you have a lot of extraneous information to provide supporting evidence of a tell or non-tell. In a blog post or comment, all you have are words. No soundtrack or scenery, no cover art or genre placement. Just words. So when someone goes on a tear about an issue, using heightened rhetoric and overstretched arguments and logical two-steps, it's hard to tell if it's real or satire. In these cases, reading becomes an exercise in finding the tell of truth rather than the tell of satire.
For example, the comment by John C Wingate in this round-up of opinions about the most recent gender bias in SF kerfuffle (you'll need to scroll down to the 7th commenter) had some very astute readers considering his words in a satirical light at first, only to headdesk when they realized, to Wright, truer words were never written. My satire radar is not very sophisticated when it comes to on-line essays and rants, so I read it at face-value only seeing their comments about potential satire afterward. Then I went back to see if I could find the tell of truth.
I thought it might be this:
For example, my writer-wife, L. Jagi Lamplighter, has not sold the same number of novels to date as have I. She took some years off to raise our children. I am also older than she, and started writing earlier. Likewise, if even a few woman authors take off a few years to tend to other duties, the statistical impact will be disproportionate. What can one do? Ask my very feminine and maternal wife, or women like her, not to like babies? Good luck with that.
That word "duties" made my AP English Rhetoric and Comp Spidey Sense tingle. It's hard for a feminist of any stripe to use such a word to describe child-rearing and housekeeping, even in jest. I thought "duties" would be a bit much for even the most subtle piece of satirical genius. But then that whole "not to like babies" bit is so over the top with rhetoric (and rife with the logical fallacy that, if women won't taking care of the babies, no one will), that I decided the piece could still be read as masterful satire at that point.
I settled on this as the tell:
There used to be a color barrier in baseball. But when Jackie Robinson broke that barrier, suddenly the managers of ball clubs found that they could no longer afford, could no longer financially afford, to exclude the pool of talent presented by the black athletes. A team who called upon a wider talent pool than its competition could, in the long run, outperform a team who restricted their talents to "whites-only."
So, I submit that there is a natural force in the free market, a profit motive, that makes prejudice of any kind too expensive to maintain in the long run. Talent will always prevail, eventually, because truly talented people never give up.
Because the example, if used and applied correctly--particularly in a stunning piece of satire--would then posit that, because we already have some women writers in the field, this prejudice (should it ever have existed) is already gone. We've broken the gender barrier. We've had our Brown v Board of Education moment and everything's now just a matter of talent. But he kind of skips that to go right for a "prejudice can't last in the free-market, because talent will out" mashup of logic that indicates to me he realized to so baldly state that any imbalance occurs because women just aren't as talented is impolitic, and changes his tactics to "well, dearies, iffin there is a problem, just be meek and humble and trust in the power of capitalism to set you free." That bit could be good satire, as well, but of a different sort than the one the original thread of logic was building on.
There comes a point, however, when faced with something so exaggerated yet genuine, that the piece becomes funny again. I couldn't get there with Ghost, but I got there with Wright's comments. The starving children in China homage ("In a world where women are stoned to death for wearing fingernail polish, complaints about lesser offenses sound shallow.") is particularly priceless.
(By the way, if you want some current numbers on gender representations in nearly every aspect of the SF field, look here.)