I think what you want to do is display the "Type" column. Try this:
- In the document library, go to "Modify Settings and Columns"
- Scroll down to the section called "Views" and select the view where
you want to add this column (e.g. All Documents).
- In the section called "Columns" you want to check the box that says,
"Type" (you may also want to change the order in which the columns will
appear)
- Click OK and go back to your document library.
Hope this helps!"