Complex sentence: When the smoker is finished, either the hose is placed back on the table signifying that it is available, or it is handed from one user to the next, folded back on itself so that the mouthpiece is not pointing at the recipient.
Split into simpler sentences: When the smoker is finished, the hose is either placed back on the table, signifying that it is available, or is handed directly to the next user. Social convention dictates that the mouthpiece and hose should be folded back on itself in such a way that the mouthpiece is not pointing at the recipient.