Actually no. It would still sound like you're saying "it's OK if it was posted somewhere, just not in a gallery" or some such. I guess I don't understand the value of the second half of the sentence -- what does that add to "image must be a new work"? It sounds to my ears like it's trying to qualify the first part in some way, but I don't see how. If the first half really says it all, why not chuck the second half altogether? "Image must be a new work". Isn't that enough? (Upon re-reading: If you don't like the notion of "new" in there (it doesn't matter when it was created, of course) then change it to "previously unpublished" or some such.) It might just help folks like me who sometimes see more complexity than is really intended...