Why do people in some photos keep staring at you, no matter where you stand?

I thought about this question when I was in the first grade of primary school. I had nothing to do in class before. I saw Sun Yat-sen, the pioneer of the Western Wall Revolution, and Deng Xiaoping, the chief architect of the Western Wall's reform and opening up. I wonder why they are all staring at me. After class, I walked around the classroom again, and the result was still the same, so I grew up under the gaze of great people. So far, I don't understand what this is all about, but I think there should be some scientific basis or some theories to explain it. Perhaps some professionals who study painting, photography or physics and physiology are more clear. Personally, I think it is related to light reflection or psychology.