Document Library, make thumbnail show

When using Document Library, I check Thumbnails in "Properties to Display». That gives me a black and white icon (JPG) in the most left column. How do I make it show as a true thumbnail of the Image? Where do I change that?

There is no info how to adjust. Do I need to change that in the code?

Appreciate help.

If the filetype supports thumbnails, the thumbnail will be shown, otherwise, a filetype icon will be used instead. The filetypes which currently support thumbnails are:

  • PNG
  • JPEG
  • GIF
  • WebP

If you wanted to add code to support other filetypes, you would need to extend that.

Thanks for reply.
The thumbnails work in other views than the default view. I tried images like .JPG and .PNG on a fresh install of Atomik and Elemental. In that table list view, there is always a generic icon of the filetyle. See Screen.
I don’t know if that is just the original layout.
Maybe it could be changed in the code.