Having reviewed several papers for Scientific Reports in the past year, it was very similar to my experience reviewing for PLoS One. You are mandated not to factor in the significance of the work and only to critique the methodology and conclusions [1]. My experience reading articles there ranges from complete junk to papers that probably just missed the mark of getting into Nature proper.

Articles should make it more clear the distinction between Nature Publishing Group, Nature (journal), and Scientific Reports (open access journal). Confusion then propagates to the headlines of the articles when posted to content aggregators, take /r/science and it's related subreddits for example.

[1]: http://www.nature.com/srep/journal-policies/referees#criteri...