Note: Thanks to @malcolmcoles for the insight.
It’s interesting to see Google are beta testing mobile unfriendly icons (the phone with a slash through it as highlighted above) in its mobile SERPS.
The new symbols are designed to tell users if a website is responsive or not however are fundamentally flawed at present e.g. the BBC has a responsive site.
And so Google adds the stick (unfriendly icons) to it’s carrot (Google started testing mobile-friendly icons earlier this month). I doubt Google will continue with both hence let’s see which one wins out after further A/B testing.