Staircase Shadows / Shadows look like faces right now I am rendering a scene with an environment map and some point lights in Blender 2.79. 
I just noticed that a part of my bowl has some weird "staircase shadow". 

The mesh should be high poly enough and it is also set to smooth.
The artefacts are rendered due to low subdivision. I reproduced them on a poorly subdevided sphere. Just add another level of subdivision and you should be good to go.