As Payback says, it takes a little while between upload and availability to applications.
MC uses the TMDB API to access the DB, and this is not updated immediately on uploading something.
just tested both of those movies and the fanart is avalable now.
Regarding the actor thumbnails,
I am going to be concentrating on TV Shows for a while, but I have plans to write a scraper library that uses the TMDB API to access any chosen field.