Is it possible to insert a jpg image inside a cell, or do Excel cells only display alphanumeric characters (or references)?
There are two ways to insert image to the Excel cell.
First way is inserting image as the background of comments.
the result will be like that
When you put mouse over the cell, it'll show the picture.
Another way what you can do is anchoring an image to the cell. You've to name the cell first. Right click on the cell, and "Define Name". then right click on the picture , add Hyperlink , choose "Place in this document", you'll see the name you'd set in the Defined Names, then Okay! You'll find out like below.
You'll need to adjust the size of the image with the cell width/height.