Range elevator is an idea by Michael Hoeltzel. It’s about having all notes “in front of you” all the time. To go up in the range, you take the elevator up, and reach forward to the note. To go down in the range, you take the elevator down.
This mental “range elevator” stands in opposition to reaching up to the high notes (like, standing on your toes, looking up with your eyes). Same for reaching down for the low notes: the upper body collapses.