No idea if this is true or someone just having a laugh with the internet but an anonymous individual, apparently employed by Microsoft, has shared details on the now defunct Family Sharing Plan Xbox One feature.
Never heard of this site so I won't speculate on their credibility but the link is at the bottom of the post if you want to read the full blog post.
"When your family member accesses any of your games, they’re placed into a special demo mode. This demo mode in most cases would be the full game with a 15-45 minute timer and in some cases an hour. This allowed the person to play the game, get familiar with it then make a purchase if they wanted to. When the time limit was up they would automatically be prompted to the Marketplace so that they may order it if liked the game.
We were toying around with a limit on the number of times members could access the shared game (as to discourage gamers from simply beating the game by doing multiple playthroughs). but we had not settled on an appropriate way of handling it. One thing we knew is that we wanted the experience to be seamless for both the person sharing and the family member benefiting.
There weren’t many models of this system already in the wild other than Sony’s horrendous game sharing implementation, but it was clear their approach (if one could call it that) was not the way to go."