Here are the instructions again, just in case you missed something.
I modified them a bit to hopefully make it easier.
To add in a picture...
1. Right click on the Picture and a small popup window will appear.
2. Choose properties.
3. Another box will appear, showing you info about the image.
4. Use your mouse to highlight the address (URL) field (looks like
https://community.auctionsniper.com/infopop/icons1/icon4.gif)
5. Right Click to Copy this text to your clipboard. Then hit [Cancel / Close].
6. Back in the message window, position your cursor where you want the image to go.
7. Click on the button and a box appears at the top of the screen.
8. Right Click to Paste in the images address and click on the [OK] button.
9. Click on the [Post Now] button and admire your handiwork.