It all just becomes a lot simpler when you realize that Yaniv has autogynephilia to a pathological degree and is also Coo-Coo Banaynays.
He wants to see pussies in the change room. He wants to offer, and be offered, sanitary products by females on the cusp of puberty. His entire brain is hyperfocused on being feminine, appearing feminine, being referred to as and complimented for his femininity, and being treated in every fashion as though he is a woman, up to, including, and especially if the parties in question are forced to do so.
"Then why doesn't he transition?"
I have no idea. Apparently lots and lots of these lunatics don't, and don't actually want to, which is the difference between AGP and being trans. In Yaniv's case in particular I'd hazard a guess and say there's a perverse pleasure he takes in very obviously being masculine and wielding the power to make people act and say otherwise under threat of legal action, and also it gets him money.
He's very clearly sexually fucked up also so there's likely a masturbatory angle to it to some degree. Maybe he can't afford it, or the waiting list is too long. I don't know. It seems like he doesn't have much interest in transitioning or passing to any significant degree when his biggest concern is forcing some poor woman to handle his sapphic junk.