And, that the US is obviously not "one" would seem to imply that it is neither "under God" even though Jesus, died, was buried and rose again in order that we could be one... maybe I'm thinking too much into it there but that's what art is intended to do, I think, cause you to think about how you should interpret it as much as we should think about how to interpret a writing. And, not that I always do but, I like to start with one of the communications when attempting to interpret such things, the rule of charity which thinks the best when the message isn't so clear.