Um...She wasn't just fat. lol
If she was, I'd sleep with the woman that was just fat.
I just Googled "Really Fat Bitches". The fattest example was approximately 1/2 the size of the original example.
It's the idea of pitting the worst, God awful example of what you are used to, versus, more or less, the best possible example of what you are not used to...Aesthetically, as RoM mentioned. Biological steers this thing in a direction unintended, really, but is yet another perspective. RoM mentioned that biologically, if the rhino, Brad Pitt and you were left on an island, nobody would be getting fucked. Obviously. From the get-go it is a given that you DO NOT want to end up with either choice. This really boils down to aesthetics only and how far to you have to be pushed to alter an aesthetic preference, in a completely unrealistic scenario.
I'd still say, for those that have brought RL tendencies into this, that attraction, and being able to "get it up" (without pills), is a pretty obvious indicator of what label you give yourself. We are dealing with a scenario (in my case and example) where I am attracted to neither, yet I find one example to be over-the-top sickening and completely impossible for me to go through with (given the aid from pills - the only way possible). One of the two choices will ultimately win by what is nothing more than default. It means nothing.
I think for each individual, there is something, and some possible example that hits home for them, that would force them to make the same decision. Whether or not they admit it is another story. It's not wrong if you don't admit it. Some straight people would still fuck the most eye-displeasing woman over the most eye-pleasing man. To me, that is disgusting. Jabba The Hut, no matter the gender, no thanks.