Yes, this is powerlifting - as long as ass, upper back and head is on the bench it's legit press.
It's not her fault that your technique sucks donkey balls.
You are correct, unfortunately this is the direction powerlifting is heading, that might be a legit lift but that arch is way
too excessive IMO, that along with bench shirts, monolift on the squat, squat suits, they even have deadlift suits now, powerlifting is
becoming a joke, the strength magazine MILO wont even cover powerlifting anymore, I love powerlifting (RAW) and always will but right now it's dying
a slow death and the only way back is to get rid of these silly suits, monolifts and excessive arching, there's nothing wrong with a tight arch but like someone said it looks more like a decline bench than a flat press.
Regards.