|Bing to Roll Out Its Own Mobile-Friendly Algorithm Update : eAskme|
The main difference is that Google gave date as to mobile-friendly update but Bing has opted vague approach. Bing has not given an exact date to it`s mobile friendly update, so I can`t tell you when it will hit the floor.
Second difference is that Bing always keep balance between relevance and mobile-friendliness but Google mobile search results now only showing Google mobile-friendly results.
According to Bing if the content have value for the user than it will still include it even if it is not-mobile-friendly.
Bing’s Criteria to Determine Mobile-Friendliness
Navigation – The Links, buttons and menus on the page should be well spaced and large enough.
Readability – The text on the page should be readable.
Scrolling – The content should fit within the device width.
Compatibility – The content should be compatible with the device.
Read More : Free Responsive Testing Tools To Test Responsiveness
You need to optimize your site on these factors for Bing to consider website truly mobile-friendly.