The problem with trying to sue Disney isn't so much that they have have more money and better lawyers as it is how you went about submitting your art work to them.
It goes along the same vein as if you submit art or a story to Marvel in hopes of being the next great comic artist or writer. If your submission includes any of their characters they own all the rights to them and can freely use any art that they have on file for advertising.
You used promotional photos that were the property of Marvel/Disney for your resume. Therefore they still own it even if you designed the background used. That leaves them free to use your idea as they see fit and change it accordingly based on their advertising needs. They changed it just enough to make it different than yours to protect their interests in the copyrighted properties.
Now if say you used an entirely photo manipulated image of a hero of your own creation with watermarked copyright on the image to show what you can do, and Disney comes out with a movie based on that image. Then and only then you might have a case. But only because it would be your property.
Here is an example.
Back in about 1997, myself and a few friends got together for an idea we had for an new comic universe. We were in the process of starting our own publishing company and were weeks away from releasing our first issue. Our concept? It was to bring superheroes into the real world. These heroes would be people that would just wake up one day to find they had super powers. the back story would have been found to have been creations of an secret government experiment. The idea fell through due to time constraints and money issues by all involved.
This idea we were working on was promoted in fan forums and chat rooms to see if there would be any interest in it. About nine years after we closed up shop without bringing out issue number one of the first of our titles ("the Dreamers") Heroes comes out on NBC. The story pretty much identical to our idea, only with different characters names and a few power changes. We never kept up on the copyrights so we didn't have anything to go with. Also since our characters wore the traditional hero costumes and the characters on Heroes did not, we didn't have anything to go with.
Great idea, but nothing we could do in court.
Next time use stock photos or ones you have taken yourself. make sure you copyright your images. You can do a poorman's copyright bu simply mailing ther art to yourself and not open the envelope. The post mark on it envelope will show proof of date of creation.
