Cell Comments with an Image
This feature probably won't hit your "TOP 10" Excel features you use every day. Most people who build spreadsheets don't use cell comments that frequently, so it is hard to get "tired" of seeing the same looking cell comment. However, it is not too difficult to dress up your comments if you are a frequent user of cell comments.

To see how it works, we have to have a cell comment. First you select the cell where the comment will be.
Then click on Insert + Comment to get started.
The black cell comment appears. If you plan on adding an image, we suggest you add the image BEFORE your text.
Point your Mouse at the border of the comment rectangle and double-click.

This will activate the Format Comment Wizard.
Select the Colors and Lines tab to view the choices found there.
This should bring up several options. We are interested in the Fill option.
Clickon the Down Arrow to display the choices.
Select the Fill Effects option at the bottom.
You have four tabs of different Fill Effects.
We are interested in the Picture Tab.
This allows you to select a picture. Click on the Select Picture button and navigate to the location of the image on your computer system.
For purposes of this tutorial, we will select Blue hills.jpg located in the Sample Pictures folder.
In a realistic attempt to insert a picture, you would navigate to the picture of your choice using the typical nagivate-to-a-file process suggested by your computer's operating system.

Your image selection should be displayed. If this is the correct choice, click on OK.
If it is not, simply Cancel and select again.
When you hover your mouse over the appropriate cell, the image will appear as a background of the comment. The choice of text for the comment should contrast with the background image if it is to be read. This is why we suggested you not add text first.

Remember that your image will be significantly resized to a smaller version. Any text in the image will also be significantly resized. The text would have to be very large and contrast well with the image to be read.