@lego what a cool magic idea, and even going pre-photo era for the backstory. very epic.
mine is a bit of a weak one this time round. also partly because I've lost my mojo for gap filling so it'll sound more like a summary than an explanation. Also sounds more like a type of magic in a larger system, than a magic system on its own. I can't quite get my head around that yet.
-Use of spatial magic to compress items into photographs, for storage/transport.
-Only non-living things
-Uses specially crafted photopaper (imbued with spatial magic)
-An item can only be stored in an image that is as large as it is. So to store a car you would need a 2mx4m piece of canvas, and then roll it up. Let's assume largest dimensions count, so an item might look smaller from a certain angle but that wont mean it fits in a smaller sapce.
-The larger the item the more energy and skill is needed to transfer it in and out.
-Multiple uses risk damaging the item or making the photopaper unusable.
-The photo will weigh the same regardless of the weight of an item inside it.