It only over exposes videos not videos
Do you mean it "overexposes photos not videos"?
The photos you show are what's called "difficult lighting". The problem is there is a bright light (window) in the scene. Cameras will try to average the exposure of the entire scene, while giving preference to the area of focus . In the photo, the center of the picture is the right edge of the pillow. The camera is trying to expose the pillow correctly, but in order to do that, it will overexpose the window. This is normal. When I look at these kinds of photo, I don't see anything unexpected. To avoid something like this, try not to shoot where the back-lighting is strong. Anytime there is bright back-lighting, and you focus on something in the area outside of the light, the background may look overexposed.
You might be asking why the video didn't overexpose the window. The reason is because the "scene", while it looks similar, is not the same. The focus point in both screenshots are not the same. This is why it's called "difficult lighting". Cameras don't have the dynamic range of our eyes, so while to our eyes everything looks balanced, cameras can't capture the scene that way. Just small changes in focus point can change the overall outcome of the photo or video. Its just the way photography works, unfortunately.