Es una foto.
I have to ask a question that the answer is "Es una foto."
What I have come up with is "Que es eso?" But that doesnt seem to be right!
You would be fine using that, but you forgot the accent on Qué.
¿Qué es eso? What is that?
"Es una foto." It is a photo.
Probably they are asking for:
¿Qué es esto?
xox, the question is asked in masculine.
I'm not sure, but I think it should be esa, because foto is feminine.