Google's Paul Haahr said on Twitter that he thinks the Google Quality Raters use their mobile devices primarily for rating the quality of the search results and Google test results. He said he isn't sure, he said "I don't know" but added "primary mechanism, I think, is raters using their phones."
Here is the tweet:
.@balibones I don't know. The primary mechanism, I think, is raters using their phones.
— Paul Haahr (@haahr) March 31, 2016
This makes absolutely no difference in your rankings but for Google to tell quality raters to go mobile shows you how Google is thinking.
Forum discussion at Twitter.