strange looking windscreen on this Vespa

looks like an aftermarket windscreen, which had a solid front and top, and a soft material dropcloth on the back

From the image below, it seems to have been for use with a delivery 3 wheel Vespa if you wanted to adapt your scooter with a delivery box 2 wheel rear axle

https://www.facebook.com/marcantoine.giorgi/media_set?set=a.10154436205530236.1073741840.524390235&type=3