A lone unicorn stands up against the oppression of evil.
But is that the case??
We listen to our stereotypes, and interpret the image as the image is portrayed. Maybe we judge too quickly. Do we have all the information? Do we really know which one is evil, and which is good?
How do you know that the dragon is not actually clinging to that rock in fear? Maybe the unicorn has gone beserk, and is going to attack the dragon. This is fantasy after all. How are we to know that the unicorn doesn't have some magical power?
Yes, the piece looks like it should be interpretted with the dragon as evil, and the unicorn good. But again, what if i, the artist am biased? What if i purposefully want you to interpret the scene in this way?
This basically all boils down the old phrase of 'don't judge a book by it's cover'. Especially if you don't know all the facts, and are just assuming. I myself have assumed things about people before, only to find out later that my assumptions are completely wrong.
So, be careful what you think. Or you may end up siding with the evil yourself.... without even realising.