Explanation of the ending of "It Follows"

Question

The ending scene of It Follows seems pointless to me.

Jay and Paul walk down the street holding hands, and someone (I guess, the demon) follows them.

Did I miss something?

Answer 1

The trick ending was discussed in an interview in Vulture with the Director; David Robert Mitchell. Although he seems to have intended to leave it ambiguous, the general concensus among critics is that it was pretty heavy-handed:

Q. The movie ends with Jay and Paul walking home. A ways behind them, we see a teenage boy walking in the same direction ... it might be the monster, or it might not. Was that always the final shot?

A. Yes, for sure. We had a couple variations on it — I think we had some where he was really far back, and then some where no one would ever miss him — but we settled on the one where he’s there, but not too close. It allows people to make up their own mind of what it means.

Answer 2

My guess is its Jeff as a Demon. I think he had the same haircut, beard and clothing. As you remember it always appeared as known people to the cursed ones.