Alamagro has a very strong one hand backhand. His arm is very free and loose, maybe one of the loosest arms on the ATP. Maybe that looseness also contributes to his serve. ?
This video was to display the unusual eye contact on one particular serve. Closing the eyes is not typical for Almagro or any server. Most servers, for most serves, break eye contact with the ball just before impact. I believe that they usually don't watch the ball until impact to reduce stress on their necks from their service motion. To see if servers are watching the ball requires high speed video and is best seen with a camera view from the side.
Almagro serve, close-up from the side, 240 fps.