This movement is a variation on the cadeira/paralelo, part of the ginga, but is considered a movement in its own right.
When practiced frequently, you'll develop strong legs and core, which gives you the ability to move freely in low positions. This form of strength will benefit you in all movement disciplines - particularly Capoeira. It's the same stance as the paralelo, except you flow from one side to the other, switching you arms and waving your head.