What makes Trailer 2 look so real?

Digital Foundry examines light bouncing through rooms, reflections, and character rendering.

The team’s chapter list makes this easy to sample. Jump to 7:07 for global illumination, 12:35 for reflections, or 27:00 for the discussion of character and hair rendering.

Keep the original trailer handy for comparison. Rockstar identifies it as a blend of gameplay and cinematics, which gives the technical discussion its context.