I believe this has started happening since the 1.4.1 update as I've not noticed it before. We were in slow moving traffic on the motorway with android auto / waze running and very frequently the blind spot camera would pop up (see attached photo). I couldn't find which setting it was to disable it, any suggestions are welcome !
That is part of the functionality of the blind spot safety system. It shows up automatically when you are at slow speed to help with judging distances. You can close it with the x or move it to some where else on the screen by pulling it.