I've run into an issue multiple times relating to copying and pasting screenshots and other images.
When creating a ticket based on an email, copying and pasting the email (including images) works fine (for me) and the images remain visible when I re-open the ticket but when someone else opens the same ticket the images don't load.
The workaround is to copy and paste and then download, save and upload each image. Obviously this can get painful if we're talking about a lot of images in an email.
This isn't an issue for me exclusively, if ticket is created by someone else the same way then I can't see the images but they can.
We are using Gmail and Chrome.