The gym where I work out is filled with Dorian Yates (old) personal equipment. When he retired and sold it all, the owner of my gym flew to England and bought most all of Dorian's equipment - including his pullover machine. Sadly, not the one in the video you embedded, but VERY similar.
That type of pullover machine is set up for lats. If you do dumbbell pullovers on a bench, you can really target the chest. Another Mr. Olympia called them the "upper body squat." That guy is Arnold. Frank Zane, a 3 time Mr. Olympia, also did them.
A video from this millennium:
https://www.youtube.com/watch?v=AAjlNtI1NiI
same guy 5 years later with more details: