A man on stage in the act of jumping, with a little boy in the background really enjoying it.
A boy happily watches an acrobat jumping on a stage.
Just because the man on the stage is jumping does not mean he is an acrobat.
We have no idea if he is happily watching, he could be feeling a number of emotions.
One does not have to be an acrobat to be jumping on a stage. Jumping is a very common thing to do on stages for some reason.