Slightly smaller in size compared to the square empty flask but more rectangular to match the icon, obviously in each colour they'd make a nice collection to display.
I would like to see every item be usable as deco, but this would be a nice one. Potions and Dyes seem like easy wins with a bit of scaling and color swapping.
seriously thou, scrolls pots and regs just crossed my mind yesterday... those would be a fine start. Then I see these old maps of citys still looted,it would be awesome to be able to double click those and have them open to appear like a map and be placeable, perhaps with decal system. =)