Juno yells at them for doing body horror stuff to scare people.
But later, she essentially instructs them to do just that....
What is the difference? Why is one wrong and the other right?
Doesn't make any sense within the movie's universe.
I thought the problem was in the beginning the Deetz's could not see them, so what was the point? When they do it later on they can be seen. The scene where the Maitland's are hanging out the window suggests that after Beetlejuice scares the Deetz's they somehow have the ability to see ghosts.
Was a little confused by that part myself, that's the best I can come up with.