This appears to be a test. A green "safe" label will appear in Microsoft Bing search results for search results that are over HTTPS. I don't think even Google has ever tested a safe label in search results, even though Google has an HTTPS ranking boost.
Here is a screenshot:
This was pointed out to me by Frank Sandtmann, someone who sends me lots of Bing-related changes. He also saw that this was tested with a gray "safe" label.
I asked around if others see the label and some don't, others see it in gray too:
– Mayank Parmar (@mayank_jee) November 20, 2020
I see but mine are a bit different pic.twitter.com/lTm5KcANKV
– Pedro Dias (@pedrodias) November 20, 2020
I can see, but with small variations in the graphics on Chrome and Edge. pic.twitter.com/Sq1OxPIAA5
– Praveen Sharma (@MusingPraveen) November 20, 2020
I'm not sure I like the "safe" label in search results, but it's fun.
Forum discussion on Twitter.