Images on invoice template

I want to add another image to the footer of my invoice. how would I go about this as there is only one option for the Logo on the top. I tried looking at the template, but I don’t understand the lingo.
thank for your help.

Upload the second image to some image hosting site such as www.imgur.com or encode image using base64. There is a tool for that: http://www.base64-image.de/