New pre-Alpha images for Mafia 3 have surfaced in a GDC 2016 presentation from March.
The presentation was conducted by Hangar 13 designer Seth Rosen during his talk titled Adding Life to your Level. You can have a look at the full thing over on the GDC Vault.
We pulled the images off the document, so they aren't the best quality and aren't very large. You still get an idea of how the developers are bringing 1968 New Orleans to life, though, with pedestrians filling up the streets, folks enjoying themselves in a Jazz Club, and protagonist Lincoln Clay even checking out a lady walking by.