Oh, I see. I did read some explanation about that when creating the comm but I got the sense that only posts with links to known spam sites or such would need moderation. I guess it's the other way around then, that the links need to be to a whitelisted place. I think I'll just change the setting to non moderated. Thanks for the help :)

//ETA yeah that was it for sure, the entries that got stuck had example icons hosted somewhere other than LJ itself or the whitelisted Imgur.