It seems to have been approved... Perhaps a glitch in the system, since I can't imagine that any of our mods would not approve the cover but approve the child posts.
Not a glitch, none of the series was approved at the time.
Approvals don't happen instantly, and more recently posted images being approved before less recent ones is not uncommon, especially when they're only a couple of hours old.
Yeah, the reason I was a little confused was that these were the only explicit images I'd posted - the two worksafe images had been approved but these hentai ones hadn't. That made me think there was something about the nature of the sex that broke the rules (although there's absolutely nothing that I could think of that would be).