Adjust the transparency and opacity: If you want to blend the image into the video, you can try to adjust the transparency and opacity of the image. By reducing the transparency to an appropriate level, the image can be blended with the background.
Add shadows and highlights: You can add shadows and highlights to increase the realism of the image. This can be achieved by adding "shadow" effect and "highlight" effect to AE.
Match the video with color correction: If you want the image to look like a video, you can try using the color correction tool to adjust the color and saturation of the image. You can do this by using the Color Correction effect.
Synchronize the image with the background: If you want the image to look natural, you can use the motion tracking tool in AE to synchronize it with the background. This will make the image look more natural when moving in the video.
Adjust the shape of the image with mask: You can use the mask tool in AE to adjust the shape of the image and make it better integrated into the video.
These are some basic skills to make images look natural in AE. The specific method depends on the effect you want to achieve and the nature of the image.