What's the ES for?

Got the Smoothie ES out for a spin with the panniers. This isn't my normal ride so it's an adjustment. Feels like driving a van when you're used to a sports car. I bought this bike for touring 3 years ago and didn't use it much so I gave it to my son, Daniel, who needed a bike at college. It was nice to ride it again. I still need to add the handlebar bag and adjust the gears. The ES is for "extra smooth".