That is a known issue we often have with the thumbnail scraper: if your post has more than one image in it, the thumbnail doesn't always pick the correct one. The same issue occurs with challenge threads with the ### Latest WIP ### tag if the post has more than one image. I assume this one is set to pick out the image in the first post of any given thread.
There unfortunately isn't anything us CL's can do about it. If you do want it fixed, I would recommend that you go edit your original post and remove the other two images to make sure the correct one gets picked for the thumbnail. I can of course do that for you as well, but I don't really want to go edit anyone else's posts, unless I've specficially been asked to.
As Wminish's post above says, we'll have separate nomination threads again, same as the previous years.
You can post your nominations there once we get them set up.