Easter Eggs and Hidden Details in VTMB2.

Sonia

The painting of a woman is the Portrait of Sonia by Henri Fantin-Latour.

You Look Lonely

A neon sign on rooftop of the Auto Repair says "You Look Lonely", which is a reference to the famous "You Look Lonely" scene in the Blade Runner 2049 movie.

Police Officers Help

Talk with a person with red aura person to get attacked and then run to any police officer with yellow aura to get help.

Wilhelm scream

In your first encounter with Willem in the Find Willem quest he will scream and if you have the subtitles enabled it will say "Willem (screams)". This is a reference to the famous scream sound called "Wilhelm scream" from The Charge at Feather River movie.