Idk, I've seen so many fakes I could probably call one in a second.
Chatgasm photos have been additionally processed in photoshop to cover up the otherwise obvious skin burns and marks, so it's a little harder to determine they are fake. I tried to highlight some of the details in red, they are good enough at least for me, i'm sure most people might not notice them.
Anyway, there are more signs that gives them away that I wish I would not explain in detail for obvious reasons (scammers do follow this section of the forum). But basically, it's the eyes, teeth and their unnatural/correct position. Also, the overall image light source is fucked in 90% of the time with over/under-exposed parts, light unevenly distributed illuminating the face in a very unusual way.
I don't know if i make any sense, i wish all fakes would look like this - image.