Perhaps he shouldn’t have said it exactly as he said it, but I tend to agree with you.
It isn’t that Hannah is an unattractive woman, or that there is anything wrong with the clothes per se. It’s just that that particular type of clothing seems totally wrong for her build.
If sexiness is her aim, she would come closer to achieving it with clothes that are more suitable to her body type. Those clothes make her appear to be trying to be something she isn’t, and missing the mark.
While I agree that skirts that short aren’t becoming after a certain age, it’s more that the outfit isn’t becoming on her regardless of her age, imo.
I’m not sure Tony thought that much about it. On first glance, the outfit looks hilarious, and I think he just went with it.