HTML formatted signatures also allow to embed images which are sent with outgoing messages. To add an image to your signature, first check the HTML signature box. Then find an image file on your computer and drag & drop it into the signature box. The image can be moved around or resized within the editor box using the mouse.
Note: Instead of pulling and image file into the editor, you can also paste an image from your clipboard after copying it from another application or browser window.
Open the image in an image viewer or browser window, then press Ctrl+C to copy it, click into the signature text box at the position where you want the image to appear and press Ctrl+V to insert it from the clipboard.