How's he liking it?

Hi, how informal or correct is the question ‘How he’s liking it’?

Many thanks,

TOEFL listening lectures: A lecture by a professor of Fine Arts[YSaerTTEW443543]

It’s very informal.

How about such a situation (I am just curious):

A: Look, John is eating Sashimi for the first time!
B: How’s he liking it?

Since “liking” is used here to refer to a temporal or on-going experience, the form is kind of being forced rather than informal. I am just supposing, though.

I agree that it’s quite informal, and that the question asks how someone likes something temporarily.