It's possible that the resolution of your picture is too high. That's not necessarily dependent on the size of the photo itself. You might be able to change that on your camera, or there might be a way to do it on the computer.
Uploading photos
I was hoping one of the more experienced denizens of Audiogon might be able to assist me. I am having problems uploading pictures for placing a sale add. The pictures are PC size, so should not be too large. It has been a while since I have sold anything, but I am doing what I can recall always doing in the past. Anyways, I get a screen that says the files are uploading, but the photos never show for captioning, even an hour later. I am using a HS hookup, so it should not take long. Puzzled. It is so frustrating, that I placed my last add on E-Bay after two days of farting around attempting to place an Audiogon advertisement. I'm sure it's me, but I don’t know what I am doing wrong.