The image size of the structural pieces of the mast on the sensor would be small, and only a relatively small number of sensor pixels would be involved in producing an image of the mast. It could be resolved by the sensor in good lighting conditions. But even strong backlighting in daytime might “washout” the mast.
In this case the sensor was overwhelmed by the bright light. The camera had insuffient time to auto-adjust to the change in brighness. That particular sensor may be back-illuminated to maximize the amount of light being captured and converted by each pixel.
I may be getting myself in trouble here ... Read even more