Concept art must be approved by our licensor before we share it, so unfortunately that is not something we could share early.
If you mean sharing artwork (or world) that is still in development, yes we can do that.
For example, Minas Tirith is in very early prototype but not something we can share. (Our licensor needs to review it first.) Some of the Gondor landscape we're developing is probably fair game.
The difference is subtle but meaningful.