Add preview and thumbnail features to document library
Some handwriting documents are scaned as images in order to put on my SharePoint site along with some Word documents, instead of moving back and forth between document Library and picture Library while browsing the datas, I prefer to put my images and documents in a single document Library. However, when I did this, I found that the image preview and thumbnail preview is not available in a document Library( I have added the image content type to the document Library ), I could add a preview column to the list view of document Library but the preview image just don't show.
You can find more details in this question that I posted :
Michelle Huck commented
I'm using Sharepoint Online 2016 via O365 and the following process works for me:
In Library Settings, create a new column.
Column Name = Thumbnail
Type = Hyperlink or Picture
Format URL as = Picture
This column will now automatically show thumbnails of your documents!
Mr. Courtney Dulany commented
Have you tried making a single line text column with the title "Thumbnail" in you document library. This works in SharePoint Online in the modern library.