If you look at the picture a bit closer, the sail is on the strap bending the batten
you being a speed sailor would have heard the phraze, closing the gap.. I thought that too the first time I looked at it.
i didn'e see that oops ....nah i don't do speed....but anyway doesn't that affect the performance of the rig??
na back in the day, they say it was faster, no wind getting wasted under the sail, we've all seen the real old Pryde and Gaastra video's, a million times..