I uploaded an image to my DAM and used it on a page with the default smart crops that AEM generated for my profile.
Now, I went back to DAM and changed some selection in the smart crop for one of my sizes where in for my small size smart crop I wanted to focus more on the object.
But after saving and re-publishing the image, the page still shows the old smart crop. If I hit the image url directly on the browser, then also it gives me the cached image, but if I append a query parameter to the url, it gives me the changed image.
Just fixed this with the great support people of Dynamic Media. The issue was that the default invalidation template of <ID> only takes care of the main asset, and doesn't flush the smart crops. The solution was either to add the specific path to the required refocused smart crop in the confirmation dialog ("The following URLs will be invalidated in the CDN"), including the crop name, or to modify the template so that it mentions the main asset plus all possible smart crops: <ID>
Edit: adding screenshots. Other instructions are standard, found under the link in the accepted answer.