why weren't these three approved? They're just part of an ongoing series, I don't see any problem.
That's what appeals (under "Options" on the left side panel) are for. It might just depend on who was online on those days, considering as an owner-level was uploading some of these in the pool. I tend to think there should be different standards for a comic with a story than just "here's an anime character I drew", but not all approvers do.