Honestly, the money makes it weirder imho. I think it's valid not to want someone to take a compliment the wrong way so you say it as you're leaving or in a context where it's clear you don't want anything from them, but being so extra about it is weird imho. Like, sure he didn't leave a number, but if he just casually complimented her that probably would have been fine and not weird at all. I imagine the note was an excuse to add the money, and he said open later to avoid her feeling weird about the money. It's his money he can ostensibly do what he likes with it, but I would feel at least a bit creeped out if someone randomly gave me money because they liked my appearance.

I hate articles that are essentially "we turned a tweet into an essay", but I don't think the takeaway is that money makes things less creepy.