To add a server icon, log into Multicraft, select and stop your Minecraft server, then follow these steps:
Size: 64x64 pixels
Upload the Icon:
1. Log into the FTP section of your Multicraft control panel.
2. To do this click "Files->FTP File Access" on the left hand side of your servers control panel.
3. Log in to FTP using your Multicraft password.
4. On the left hand side click "Upload".
5. On the next page click "Browse" on the left hand side. Then choose your icon picture.
6. Click "Submit" and wait for your file to upload.
7. Click "Back" in the top left.
8. Click the checkbox next to your uploaded image.
9. Click "Rename" at the top.
10. Rename the image to "server-icon.png".
11. Click "Submit" and restart your Minecraft server.