I do not honestly know much about patents and the wording of laws, but on the Wiki page about Design Patents the phrase "Thus a design that was arrived at independently can still infringe a design patent." seems troubling. Hopefully it's as Perceval says, that they are just covering their ass from patent trolls.

Also Google's patent for "Collaborative web page authoring" http://bit.ly/2t287H seems more disturbing than the design one.