La photo, c'est ton truc?

Does photo here mean photo in English or photography?

I'm sending this to our French expert, Mme.

The difference in French is:

photo = la photo
photograph = la photographie
photography = also la photographie
photographer = la photographe

For #2 & #3, often you can tell by the context, or exactly how the word is used.

Sra (aka Mme)
I'll flag this so I can return later to see if you have any other questions.

In this context, "la photo" refers to photography in general, not just a single photograph.