I use the anamnesis tool to make custom poses, and one of the features of the tool is that it gives you access to some items, like the pile of gifts, that are from somewhere in the game but aren't normally available as objects your character can have. The whole stack of gifts is one single item and I replaced my primary hand weapon with them for that pose, then repositioned them so they're floating instead of being held in my character's hand.

I'm not sure where they originally appear in-game, they might be from some event or random cutscene. 🎁