I have to say this sure looks like a pretty poor green screen attempt. Note the black edge around her and the flatness of the audience behind her.
The people watching just behind and under her look real, though why they would be recording her behind and her side with their cell phones is a mystery.
Clinton even claims there's a full overflow room (something she did when she visited Toledo's 900 capacity venue).
Eh, not so much. The cell phone cameras look pretty staged to make this poor attempt look real.
Take a look and decide for yourself. The audio sounds phony too, like fake cheering added to the background.