Reverse band deadlifts are for
strengthening the lockout portion of a deadlift. Some
people find it difficult when doing rack lockouts to
assume the body position they use in competition,
reverse band deadlifts are a way around that problem.
The bar is hung from bands so that they assist in
getting the weight started off the floor.
As the bar
rises, the bands assist less and then not at all.
Many thanks to Donna Slaga for providing the photos and description