The bands are caused by flicker/refresh in the subject interacting with how the camera records the image.

CFL bulbs do not emit perfectly steady light; their brightness varies with the AC power frequency (typically 50/60 Hz, or a multiple of it). CRT displays also refresh/scan at a set rate. Many phone cameras and some digital cameras capture the frame by scanning the sensor line by line rather than exposing the whole frame at exactly the same instant. If the light output changes during that scan, different parts of the image are recorded at different brightness levels, which appears as horizontal or band-like stripes.

So yes: it’s related both to the flickering light source and to the camera’s capture timing (often described as rolling shutter behavior).

A practical fix is to change exposure timing—try different shutter speeds, often faster ones, to reduce or change the banding. Results depend on how well the camera timing matches the light’s flicker frequency.