They are the builder emojis
you're right - actually all of them except the very first seem to be carrying shady boards on their heads!
Note: you have to look while he's in the box with the others, since it doesn't show once posted.
Can't speak on why those are not in the shoutbox, but why does the bottom emoji look like he's balancing a board on his head?
:stare: which isn't in the shoutbox either.
The shoutbox is unavailable to non-members