How am I bending this metal with my hands?
It's called a wave bend. Instead of one continuous bend line, you cut a row of slots along it and leave small tabs in between.
Those tabs are the only material actually bending, so a part that would normally need a press brake folds over by hand. Three reasons people order parts this way. It skips the cost of a bend, since the part ships flat and you do the forming. It works when your geometry would collide with the press brake tooling, which comes up on deep boxes and tight returns.