The simple solution is to design the card so that, at all display layouts, the last visible item is cut off -- it goes a long way toward saying "there's more in

The simple solution is to design the card so that, at all display layouts, the last visible item is cut off -- it goes a long way toward saying "there's more in this list". The new share sheet in iOS/iPadOS 13 is not great -- the two rows of horizontal scrolls (one for contacts, the other for apps) was much more discoverable.