I wouldn't consider using "picture" to refer to any artwork and I'm sure most artists would be offended to hear/read their paintings referred to as pictures.
I imagine
Ralph Goings ,
Leng Jun,
Robert Bechtle and other
photorealists,
hyperrealists, as well as anyone who practices
trompe l'oeil might disagree. It's the very essence of what they're trying to do - render a photograph via another medium.
Having sat through quite a few art critiques as a student, it's not uncommon to hear someone refer to various elements in the 'picture', or to use 'picture' as a synonym for 'painting' or 'scene'.
Regarding Goings, here's a quote from him about his own work I found on Wikipedia: (bold emphasis mine)
"In 1963 I wanted to start painting again but I decided I wasn't going to do abstract
pictures". It occurred to me that I should go as far to the opposite as I could. ... It occurred to me that projecting and tracing the photograph instead of copying it freehand would be even more shocking. To copy a photograph literally was considered a bad thing to do. It went against all of my art school training... some people were upset by what I was doing and said 'it's not art, it can't possibly be art'. That gave me encouragement in a perverse way, because I was delighted to be doing something that was really upsetting people... I was having a hell of a lot of fun..." (edited quote from Realists at Work)