I think the OP is getting a bit of a hard time - I don't think it's an unreasonable question to ask, and hopefully some of the explanations have enlightened her.
If we don't ask, we stay ignorant. OK, perhaps she's framed the question/s in a way which some might not approve of, but at least she's willing to have her eyes opened, no?
And to whoever said '...so that's your theory ruined, OP', well, she was never espousing a theory..? 
She was just wondering.
I'll be honest and say that it's something I've wondered about in passing myself and I count myself as very exposed to the gay lifestyle - my brother's gay, Dad's best friend's daughter's gay, my best friend's brother is gay, my boss is gay, yada, yada, yada.
Of course, when you think about it - it's a silly question because it's simply not true - lesbians (as if they're one great homogenous mass of humanity) don't go for women who look like men. Some do, sure. But the whole idea is brought down when you consider that it's only butch-looking lesbians that - what's the best way to say this? - stand out from the crowd. All the lesbians who look like you and me, i.e. women, are clearly not with butch lesbians (since, again, they look like what they are - women), so it's only a small percentage who go for women that look like men.
My Dad's BF's daughter who I've known since we were born is neither feminine nor masculine-looking. She just looks like herself. She neither dresses up, nor dresses down - she just dresses without any particular enhancement to her appearance - pretty much like all men do. I mean, beyond the basic maintenance and hygiene that men do. Her wife, the same (although her dress sense is definitely more vibrant! 
).