I thought this was a shitpost at first(based on the tweet/title) but no, this dude is dead serious. In his own words on a followup tweet:

'Love all the people trying to justify her and tsunade's designs like they are real people who make real choices and not two characters intentionally designed to be young and attractive. This is 2024s "this 15 year old needs to wear bikini to battle because of her superpowers" '

This guy is genuinely bothered by the way this old woman is portrayed.

On the one hand, enough anime has that weird thing where making characters actually look the age they supposedly are is annoyingly uncommon, and are usually made to look younger. So I get it.
On the other hand, Live and Let Live, who gives a shit. Grandma looking like a 30-something who dyed her hair white hurts no one, to my knowledge.