Surely we dont still need to use spoiler tags do we? I mean anyone who doesn't want to be spoiled, should probably be avoiding an FF7 Remake forum.

And yes, I think that's why Rufus could see them but Tseung couldn't. Which suggests that Rude and Reno can probably see them too. So I'm guessing when Elena appears in part 2, she won't be able to see them.