When D.J. spits out her bite of sandwich into the napkin, the napkin un-crumples on the counter and there is nothing in it.
It is obvious that neither Steph's nor Jesse's attempted recorder playing is actually happening. Their cheeks never move, or "inflate" with air, as they would have to in order to be properly playing any instrument by mouth. Also, the fingering does not totally align with the audio track that is played as the recorder sound.