Hot answers tagged performance
As you've found, technically any of the three will work. But 'photos.smugmug.com' is the domain that's really designed for this. It goes through the properly scaled layers of our architecture, from CDN to caches to photo-optimized serving clusters, and does the 'right thing'. The others will also work, and you probably won't even notice the difference, so ...
Only top voted, non community-wiki answers of a minimum length are eligible