Blurring edges not working

I’m trying to use the inside shadow style to hide the white reflections in this image at the edge of the image against the black background. When I setup the inside shadow with a obvious color, you can see that the color goes all the way to the edge and fades in toward the image. When I set it to the background image through it doesn’t appear. Why is this?

hi @charlespick here is one way how to

    background: url('') 50%/cover;
    box-shadow: 0 0 8px 8px #111111 inset;