I do like the concept, but there's a lot of loose ends. -1 is mentioned briefly, but never elaborated on. Is it the same entity person to person? Different every time?
Also, with regards to how it operates - each person gets a random image? Do all people see the same thing if shared? Can any person in a group voluntarily leave?
Execution-wise, not a fan of the blanked line. It's not a sentence that adds anything.
Anyway, answer those questions and come back. You should know exactly how your anomaly operates - I would write it all out and then cut out the boring stuff. As it stands there's a lot of things left undeveloped.
I'm interested to see how this turns out.