After you check-in you can just browse around inside the terminal. There are some things of interest there, such as a model of the Magic in quite excellent detail. Or, you can stand in the line waiting to board the ship. If you're a concierge passenger you can wait in that lounge area. There are benches to sit on in the terminal.
Of course, you only have to wait around until boarding commences. The line goes quite quickly after that. So, if you're checking in after boarding begins you may very well not have any line at all to stand in. In that case you may be checking in and getting right on the ship.
Personally, I dislike standing in line, but I do like getting there early. I just don't care for standing still. I like walking around and just looking at things or walking and watching people check-in.