Ability to choose a thumbnail for a model

When uploading a model, usually the first image when uploading is the thumbnail. I never really had an issue with this until now. Today I realized one of my models thumbnail changed. This is because I uploaded another image I generated, showcasing the variety the model could generate. This was a separate post in the gallery and not part of the main post for the model. Unfortunately this changed the thumbnail of the model and I have/ had no way of changing the image back to what I wanted. Therefor I made the decision to delete the image that was the thumbnail, and even when doing that the site kept giving me errors. After spamming the delete button multiple times, the image was finally deleted and now the original thumbnail is back. However I think there should be a way to choose what image is going to be the thumbnail, so this doesn't happen again and I'm sure there are many people who's thumbnails have changed without them knowing just because they uploaded another image. The only way I was able to see was by looking at my profile and then I realized, that wasn't the original image I wanted as the thumbnail.