That's just part of having a Stand. They all do something. No way of knowing what they do, though, without seeing it.

[He follows along, letting the doors close behind him, and lets his fingertips just barely clip against Abbacchio's side as he passes him to lead the way toward his office.]

That's why the medics were so freaked out when you said you saw one. They thought it might've been that kid's, and they couldn't even see it, much less hope to guess what it might do to them.

[And the thing is, Abbacchio's not stupid. Any second now he's going to add up the pieces and ask, so what does yours do. Is he going to tell him, he wonders? Even now, he doesn't really know.]

You should figure out what yours does. Even if you never use it, it's a good thing to know.