Welcome to the Official Redemption® Message Board!
...it would be best to examine all cards that use the "contents" wording before deciding.
Side note: "Contents" no longer looks like a real word to me, haha.
Even so, a card placed on another card is still ON the card, so I would agree in saying that the same rule applies. If Card A is on Card B, and Card A is in Card C, then Card B is in Card C. That still makes the most sense to me.
Well yes I agree with that, but the difference would be a card placed on the thing doing the holding (like Image of Jealousy on a Holds fortress). I don't think that the placed card should be considered contents in that specific case.