To add a server icon, log into your Multicraft Panel, select and stop your Minecraft server, then follow these steps:

Icon Specifications:
Size: 64x64 pixels
Filetype: .PNG

Making the Icon:
1. You will need to have a picture or have created a Minecraft server icon.
2. You can convert a picture for icon use using this handy tool: http://www.genfavicon.com/
3. Once your picture is converted. Click the "Download: jpg" to download and save it to you computer.

Upload the Icon:
1. On your Multicraft panel choose the "Files" menu.
2. Click on "FTP File Access".
3. Log in using your password.
4. Click "Upload" and then click "Choose file" to select your image. 
5. Click "Submit".
6. Go back and select your image, then click "Rename" at the top.
7. Rename the image to "server-icon.png" and click "Submit".
8. Restart your Minecraft server.