I don't get this, you're supposed to decide whether you like somebody or not with _only_ one picture while writing unique descriptions that could give you some

I don't get this, you're supposed to decide whether you like somebody or not with _only_ one picture while writing unique descriptions that could give you some insights to his or her personality is actively discouraged? I mean sure, this would work great for one night stands, but I think bars with drunk people are superior in this aspect.