How can a photo be philosophical?

I knew a street artist who never talked. He would take photos of random people in the subway, and around my neighborhood. The strange part is he would only take the photos when the people taken the photo of weren’t aware of it. He didn’t like the posing humans.

He would always wear the same outfit (or some kind of a costume, if you will.), and I also heard he has been homeless for a while. My friend overheard him speaking with his girlfriend a couple of months ago. Appearantly he was telling how people are easily affected by each other - causes of both pain and extreme joy. He also said we are all fragile and yet very powerful since we have this one life and the most valuable thing we have is each other, since we share this ‘wonder’ together.

I want to know what this guy was doing with the photos. What the purpose of his photos mean. I am sure they must have something related to what he was telling his girlfriend/friend. What do you think?