The checkmark on the sensors mean that sensor is participating in the current comfort profile as configured on your ecobee. The eye means “occupied”.
Ecobee averages those sensor temperatures together to come up with the effective temperature in your home. (61.5 + 59.1 + 60.7) / 3 = 60.4
Most cards have a menu in the top right (three dots icon). Click that, then click Help for more info on that particular part of beestat. The full documentation is available here.