Edgeworth Box Candy Sharing
Olivia (Orange) and Bob (Blue) are splitting 20 Starburst and 16 Reese's.
You can change Olivia (a) and Bob (b_1) preferences for Reeses over starburst in the 2D view on the left.
In the 3D view we see the level curves for Olivia and Bob's utility functions in aEdgeworth Box.