Unexplainable dog behavior.?

So last month I lost my dog and we cremated him. His ashes are in a small wooden box that we keep above our fireplace. We got a new puppy and he isn't scared of anything (Until this morning).So this morning I was playing with the puppy and I noticed that the box with my dog's ashes was on the coffee table. So I picked it up and held up the box to the puppy just because I wanted him to know that this was my old dog. But when I held the box towards him he got scared. I didn't know why he was scared. He just kept running away from the box and he wouldn't go near it. Why is he scared of it? Could this mean he can sense my old dog even after my old dog has ped away?