In It Follows why can Hugh/Jeff still see the demonic entity even after he's passed it on to Jay? He sees it once in the empty parking lot immediately after he ties up Jay, and there is also a scene later in the film of him telling Jay and her friends that he DOES see 'it'.
The rules are that everybody "infected" can see the entity, although it only targets one person at a time.
This is reiterated several times throughout the movie:
- Hugh/Jeff can see it in the empty parking lot;
- Hugh/Jeff explains it when protagonists trace him to his home:
Okay, even though it's following you I can still see it. It's not done with me either. Like I told you, all you can do is pass it on to someone else.
- In a later scene Jay can see the entity when it's going after and killing Greg: