Oh I see must be because of others' images.
I only upload my own images when using photography tags and following juliank and photocontests :)
Sometimes I use images from wikipedia etc for my blog posts/articles only and I do not use photography tags :)
Yes, I used it anyway in posts where there were both photos taken by me and others. In addition, I used the tag foodphotography without event knowing about the contest and its rules. I've recently read it, and I would like to take part in the contest. So, I tried to write to photocontests, but without any answer.