It was account level, if I went offline then the other person would get a notification from steam that said something like "Hooray, X's shared games are now available for you to play!"

https://lr.vern.cc/r/Steam/comments/wrwvs1/how_do_you_remove_this_notification/

If you're talking about the new steam families beta then yes that is when it was changed to be game level not account level.