"What We Do in the Shadows" is a TV series and a movie about vampires, so they are not related to what we see in the shadows in real life. However, in general, shadows are areas where light is blocked by an object, creating a darker area behind it. What we see in the shadows depends on the amount of light available and the object casting the shadow. If the object is opaque, we will see a solid, darker shape. If the object is translucent, we may see some details or colors through the shadow. The shape and size of the shadow will also depend on the angle and direction of the light source.