I asked Google Workspace Support this question few times over the years. While the answer above works in most emails, for some senders option 'Images from this sender are always displayed. Don't display from now on' is missing. Support cannot tell why.
User: I want disable images from A SENDER, some specific sender which have pictures displayed at all times since I clicked display images from this sender once.
Google Workspace Support:
At the moment, the feature you're requesting for is not currently available as we can only ask to remove the images from all sender as you may have seen on Gmail settings; however, we'd love to get your feedback in order to improve our products moving forward. You could submit a feature request to our team by visiting https://g.co/workspace/featureideas
(screenshot of conversation)