It's a capability to improve workflow for folks that need/want it. For example, say I have a client project that takes several days to build and has multiple renders that I need to compare. To prevent opening those renders in Photoshop, you can "Add Folder" to the artwork tab and select the folder you've been saving the renders too. Now, instead of program hopping, you can open previous renders from within Carrara. Works with animations too. It's also a nice way to prevent Render Room clutter by having a bunch of renders open at any one time. You can be more selective. Double clicking a file in the Artwork folder should open any 2D format that Carrara supports directly in the Render Room.