What is this "PHONE" Icon in Status Bar on Android 7??

[AC Question]

Hi All,

I've just upgraded to Adroid 7 on my Samsung S7 and a PHONE ICON appears in the Status Bar.
What does it mean and what does it do?
I cannot seem to be able to access it nor turn it on/off.

Thanks

 

[belodion]

Any WiFi icon with it?

 

[CWinkler]

Screenshot would be helpful, if you can post one