User blog comment:Kogath/Monster Hunter X Discussion/@comment-26953474-20150806202456

http://trinfo.jp/11246  something really interesting was pointed out on trinfo: not only are the knife effects blue during a mount, but when other players hit the monster while its happening their effects also change to blue. you can see in the very last gif before the hunter can get any stabs in with their knife, the hammer hits the monster in the head with blue effects and the gauge raises slightly. so maybe other players hitting the monster helps fill the gauge now?

also more obvious: the mount gauge can be seen by all players now underneath the name of the hunter that mounted.