I appreciate the remarks everyone made. Regarding studentff's comparison, I wonder if the Indonesian rafts *do* support people sitting on them. The picture on the safety card might be intended to show the *possibility* that one can use the raft just to hold on, rather than the requirement that one do so.

This is where explanation is needed. Either verbally on the card (by localizing it for the region), or by the flight attendants when they explain O2 masks, etc.