Thread: I have never seen this bench press exercise

Sounds to me like they were doing lockouts, in the power rack. The power rack I am pretty sure is what you're talking about. Where you have 2 metal pins that the bar can sit on. And if they were used only a limited ROM (range of motion) I would say that it was definitely some kind of lockouts. Lockouts are excellent for targeting your sticking point in bench. Often used by powerlifters.

depending on where the pins were lined up, they were probably working on "pin pushes". you can set them up at a variety of heights off the chest to work on lock outs for the triceps, or to help with a sticking point somewhere in the middle by pushing from a dead stop and eliminating the recoil that you would normally have during a complete lift, (down and up). if the pins were above and below, they were working on the later, and limiting the tricep involvement and involving the lats and shoulders more.