If you maintain your product images via the CMS, you might already know that large images (1000 x 1000 pixels & larger) get optimised for the web.

If you'd prefer this did not happen, you can now disable resizing and optimisation via a new flag.

Navigate to Settings → Feature Settings, and Edit the Product Media feature. 

You'll see the new Optimise Large Product Images toggle - it will be on by default, but you can toggle off and click Save if you'd like to disable the function.