I think it is a bit like the idea of a "boost glide" which the Apollo command module did during re-entry, "half bouncing" of the Earth's atmosphere to slow down its speed of re-entry. A spacecraft can do a complete skip, bouncing back into space and then do multiple skips before re-entry. But it can also enter just on the edge of a skip trajectory and turn that into a long glide through the upper atmosphere. This can let a low lift to drag ratio glide much further than it could otherwise, so in effect it boosts its lift to drag ratio. See this thesis: "Reentry guidance with extended range capability for low L/D spacecraft"