If you search using Bing on your mobile device, Bing may now start labeling mobile-ready web pages as mobile-friendly, similar to Google.
Here is a screen shot:
Bing did write about the importance of mobile back in November 2014, but back then there were no mobile-friendly labels in the mobile Bing search results.
Is this a sign to mobile factors coming at a larger level to Bing?
Forum discussion at WebmasterWorld.