How large is the picture file itself? The bigger the file, the longer it will take to upload. If it's too big, it won't load at all.
I always compress my photos before i upload. They still display in a decent size, but the files themselves are smaller in size.
Since I don't know which software(s) you use to manipulate your photo files, i can't provide more specific advice.
if you don't know how to compress, but can tell us more about your software, one of us might be able to help you learn that very useful skill. :-)