This camera is amazing - especially the night sight. Here are two sets of images taken around my house. My old phone (Honor 8) doesn't do a horrible job and it shows pretty well how much light there was (or wasn't) there. The Pixel 3a picture is simply amazing however and the amount of sharpness and detail is incredible considering how dark it really was. All images are "straight out of the camera" and no editing or processing was done by me.
These images are taken in my dining room. There is light spilling in from the Den (left side) and the china cabinet in the corners (right cabinet is visible, but there is a similar cabinet on the left side too).
Honor 8
Pixel 3aXL
These images were taken of a bedroom in my house. There are no light sources in the room and the only light is spilling in from a ceiling light in the hallway. The shadow on the right side of the bed is actually from me standing in the doorway to take the picture with the hall light behind me.
Honor 8
Pixel 3a XL
You do need some light for the night sight to work. I tried to take an image in basically no-light conditions and the picture came out black. But if there is even a small amount of light, the night sight mode does an amazing job of increasing the exposure all while keeping the amount of noise relatively low.