Is this a sign that a new mobile algorithm is coming?
There is no doubt mobile browsing is just going to get bigger. Google recently sent a warning message to a huge number of webmasters whose websites are not yet ready for mobile devices.
The mass notification was sent through email or Google Webmaster Tools under the subject line “fix mobile usability issues found on.” The message contained details on how the website may have serious errors when viewed on mobile browsers, and will therefore be subject to sanctions in search engine rankings. In other words, this is Google’s way of telling the webmasters that their sites are not mobile-friendly yet.
Those with Google Webmaster Tools received a few tips on how to address mobile usability issues, some of which include the following: check which pages are not mobile-friendly, read Google guidelines on mobile-friendly design, and fix the erring pages.
For more information about this new development from Google, check out this article.
In addition, have you noticed the “mobile-friendly” notices on mobile Google searches? See image.