The logo image (only logo, no other images) can be edited or changed in a Xplor Transactional Email template. Either through:
Edit Email:
Copy and paste the image in the header of the email text block
Or
The logo is a link in the HTML (so the actual image file is hosted somewhere) and can be edited.
If you upload an image to https://imgur.com/ to use as the logo - once you post it,
Click new post
Then need to open the image in a new tab (right click open new tab)
And use that link after the “src=“ in the html code.
Not the link Imgur gives you to copy over. It’s a minor detail but all it does is as a “.png” to the end of the link that I think makes all the difference.