If you don't already have an existing gist, you'll need to create one before proceeding.
git clone https://gist.github.com/<hash>.git # via https
git clone git@gist.github.com:<hash>.git # via sshMake sure the images are at the root of the gist and not in a subdirectory.
git add <some-image>.<jpg|png|gif|etc.>git commit -m 'Add Image(s)'
git push origin master