A model, while being filmed, is also getting her make-up. Vogue (see: 5:57-6:03)
She says: "I have been gettin my makeup done for about, what, two hours?"
When she is saying this, she can't be quite sure how long it has been, so she hesitates to give a number and thinks about it for a while and looks at her makeup artist simultaneously, and says, What?
Just as she is looking at him and saying "....What?", he says: "Two hours."
And then she becomes certain and repeats what she has heard from him: "Two hours now."
The use of "what" by her has drawn my attention, because it seems to function as "how many" and asking for a number rather than a thing, as in the case of "What do you weigh?" instead of "How much do you weigh?"
So, my question is: Is using "what" in place of "how many" correct or is it just colloquial?