We must note that Rivian Forums is not affiliated in any way with the Rivian car company. A forum member created renderings based on the patent line drawings to show what the modules could look like, so don't take them as Rivian's designs. The renderings have nothing to do with Rivian, and as is the way with patent applications, the items described might come to nothing.
The patent application, titled "Systems and methods for reconfigurable electric vehicles," identifies the setups as naked configuration, side rail, roof-height enclosed, below-roof-height enclosed, over-the-vehicle-roof recreational, and the duo of removable roof plus removable open box modules. First thing that sticks out is the renderings make Rivian's idea look really good. We agree with forum poster Electric Dan, however, who asked, "Can we get an extended bed module? An extra 2-4 feet would be a must have module."
The second obvious factor is that, as with Rivian's modular battery patent, the modular beds would likely require the use of a crane or forklift to maneuver, and plenty of room to store. Therefore it makes sense that the patent lays out use cases for some kind of public/private fleet operation. In one example this would be "a plurality of drivers (or users) of a shared vehicle driver pool, which may comprise both vehicle owners and non-owner users of the vehicles ... paired with vehicles ... of an automotive vehicle pool."
If Rivian could find some way to make the modular beds convenient and affordable to use, we're all for it. Having raised $700 million in a recent funding round led by Amazon, this idea seems a terrific avenue to explore once the sales and service operation is running smoothly, and right up Amazon's alley.