Thanks for your reply. The reason we want to hide certain content is because we use banners in our newsletter in which we have specific banners for desktop and mobile. That's why we want to hide the desktop version and show the mobile version of the banner in our mobile view of the mail. :) Hope this clarifies things.
Thanks for the reply. Kevin's code (below) worked instantly, so I haven't been able to check out your snippet, but will do that soon!
So many thanks. The code is working, so thanks for that. I also figured out what I did wrong in my sequence, so great learning moment as well!