I am a biological woman. I identify as such. I don't know what the same person plus 30+ minutes with a curling iron has to do with cheating. Effort? Vanity? This is far, far beyond me somehow. I am also very old so there's that.
I think you helped me crack it, i think it's saying that the person who looks like you but puts in more effort to their appearance on the regular is more attractive. That makes sense to me, and would be true in the main for most people, it's one of the most common things said to people who are struggling to find partners.
You could take negative connotations from that about that person being vain but really it should be on the cheater for being a fucking cheater.
I agree with you, but don't like that the interpretation puts the onus on the person being cheated on. Like, people will cheat even if they're with the most gorgeous, totally out of their league person. Cheating has nothing to do with how attractive or how attentive to themselves your partner is. If you're a cheater, you're gonna be a cheater.
I actually think what you said is the real point of the image. To me they are saying that they will cheat with a girl that looks just like you, because that's how guys be.