What was the deal with Pussy's ghost?

I never understood this part. Like he would sporadically appear in episodes after his death, like when they were having the ceremony at Tony's house after his mom died, and Pussy appeared in the mirror and Tony just happened to look in the exact spot where he would've been standing and just froze for a couple seconds. I think he was present at Chris's making ceremony too, but I'm not sure. Shit was weird, what was this supposed to acknowledge?

This one was still weighing on their minds and consciences. "Him you loved."