I always struggle to comment on photo/art post that have very few words and congratulations/milestone posts. I end up bringing up the color, the process, what aspect that I liked about the photo that drew me in. Sometimes the photo itself is the story and so I can play around with that a bit. That way they can get an understanding what their audience enjoyed about it.

I just wish people would put a little more writing alongside their wonderful photos. Some insight/details about why this photo was used. Struggles to get the perfect shot. Whatever it be.