See thru shoulders have been popping up here and there for a few seasons now. In the Fall 2014 shows they were still going strong, like here and here, from Rebecca Taylor. As we shift into spring, and want to show a little more skin, see thru shoulders are the perfect transitional wardrobe item. You can embrace spring without being so crazy as to expose your legs.
An added bonus is that you know we'll all still be sporting see thru shoulders into the fall and winter of 2014/15, if the Fall 2014 collections are any indication.