This is maybe stretching what a bag can do but anyone with a toddler or child in their house will see the immediate utility of this: namely, a bag which is large enough for all the small parts of toys children seem to have and which take up alot of room and which can be stored flat until needed.
The idea is having shaped fabric, circle? oval?- which when opened spreads across the floor (provding a play area) with all the toys "in it" and when the it's time to clean up ... all the toys can be placed on this fabric and because of an elastic cord threaded through channels at the outside edges can be instantly cinched closed. The toys and bag can be put away in a minute.
Padded? why not.
Of course, a large open out bag like this could have other uses... laundry, wood, anything which is awkward to stuff into a bag. In this case, the bag wraps around the thing.