Board Thread:General Discussion/@comment-36901631-20200108161355/@comment-3026053-20200108163644

You need to upload the image on the wiki first, in case you hadn't done that already. After that, you can just follow the format of the images already on the page.

For the gallery addition that would be to just past the name of the image (with the "File:"-prefix) and a description of the tabber title underneath the coding of the last image, like so: "name.png|Whatever", which will then make your image show up in the infobox under a third tab "whatever".

Before uploading your image and making your change, sure to check out and follow the image and other relevant policies on that wiki.