Sorry for the bad quality.
My grandfather had this in his office. He worked as a computer engineer so I initally thought it was a zoomed-in picture of a computer chip or something, but maybe it is something large.
He’s not alive anymore so I can’t ask him. If somebody can help me out, that would be great.
As others mentioned it looks like a heat sink, they create a lot of surface area and blow air through to the device in order to help dissapate heat and prevent the device from overheating.