Do Nature journals wrongly claim copyright in their published pdfs? I just noticed this and I'm slightly confused by a small detail.

The Nature Publishing Group states in its Publishing Licences page that the copyright on articles remains with the author:


  NPG does not require authors of original (primary) research papers to assign copyright of their published contributions. Authors grant NPG an exclusive licence to publish, in return for which they can reuse their papers in their future printed work without first requiring permission from the publisher of the journal.


Moreover, this is supported by the Licence to Publish agreement, which explicitly states that


  
  [...] the Authors grant to NPG [...], subject to clause 2 below, the
  exclusive licence (a) to publish, reproduce, distribute, display and store the Contribution in all forms [...].
  


and


  
  Ownership of copyright remains with the Authors, and provided that, when reproducing the Contribution or extracts from it, the Authors acknowledge first and reference publication in the Journal, the Authors retain the following nonexclusive rights: [...].
  




However, the published articles have a clear Macmillan copyright marker. Taking this paper as an example:


  




Is NPG wrongly asserting copyright to the entire article? It is my understanding that they could still be claiming copyright over the copy-editing and formatting, but since they have explicitly opted for a licence to publish instead of a copyright transfer, it seems to me that they should be crediting the authors with the copyright, e.g. along the lines of 


  © 2015 Qian Wang, Edward T. F. Rogers, Behrad Gholipour, Chih-Ming Wang, Guanghui Yuan, Jinghua Teng and Nikolay I. Zheludev. All rights reserved.


for the above-quoted example, with whatever legalese they felt necessary to indicate that they own the exclusive publishing licence. 

Is there some interesting detail about copyrights that I'm missing here? Or is this simply a fudge?


I understand that this is not a big question and that it is on the edges of this site's purview, but I still think it is interesting. If the community decides that this is too much on the legal-question-answerable-only-by-a-lawyer, would migration to Law Stack Exchange be appropriate?
Given its position on the page, and in light of the details you posted, I suppose (as is speculated above) that the copyright applies to the document presentation, not its content. Of course, IANAL, and you might very well learn more at the law.SE.