Thumbnail preview for file column

[HSAI]

It would be useful to be able to display a "file" column as a thumbnail in the same way images can be. 

For example - I have a form view to upload a pdf file, and in the detail view for that record I can see a thumbnail of the pdf document rather than just it's name

[dbaum]

Consider using Apps Script to populate an image column with each file's thumbnail.

[Nick_Haschka]

a built-in PDF viewer would be really helpful for a number of apps that I am building