There are two pictures in those tweets which look to be potential NCAA violations:
1) The tweet from Terence Carter looks to be in a Hotel banquet room with multiple chairs and tables set up, along with AV and Technology equipment. Typically, this type of facility and IT equipment at a Hotel will cost at least $500 - $1,000, so who fronted the bill to pay for this? As previous posters have said, the recruits cannot have access to the coaches and the visit cannot be sponsored or planned through the university, so who was giving the presentation to the recruits? In addition, I'm sure there is a breakfast or buffet lunch behind the recruits.
2) The since-deleted tweet from Tristan Leigh's Mom where it shows all of the recruits and their families in Oklahoma's football stadium on the field. How often does the public get access to a school's football stadium and the ability to go on the field? RARELY. By the way, I don't see any pedestrians in the football stadium.
There is a reason why LSU's Head Coach called out both Oklahoma and Georgia for their recent recruiting visits.
The reason why we are discussing this situation is most people would agree that Penn State's biggest recruiting sell is getting the recruits on campus and selling the university and the football program in person. Clearly, Penn State is abiding by the rules, but other schools may not be.