If he rewinds using Moody Blues, it's clear there's a huge gap of time missing from what will be able to be replayed. The rewinds that Moody Blues will be able to procure by rewinding at parts of the mall will still be happy shoppers - so no clear hints there about where all the people went. At different areas of the mall, if he were to replay some of the mallgoers it'd generally just be people shopping. Listening to their conversations will let Abbacchio know that many of the hot topics these shoppers gossiped over varied quite a bit. Interesting points will include, "Oh, the conditions outside are really worsening," or "We just renovated our house to filter the air!"

If Moody Blues rewinds far enough, specifically where the Santa chair is, he will also be able to find each child that appears in the photos, confirming that these children were there at one point.