It’s a Sankey plot: a multiple viewing levels plot where the width is proportional to the quantity represented.
Taking into account predictive own and cross elasticities, it explains where the volume is distributed, i.e., where it goes or where it comes from (as the case may be) when the user increases or decreases the price by 1%.
Visualize how the cross effects affect your products (Cannibalization Loss/Steal) and your competitors (Competitive Steal/Loss).