The tick marks on the temperature dial are showing you the temperature setpoints that are currently set on your Embr Wave for warming and cooling. This is the temperature level that your Wave will go straight to when you single-press on the cooling or warming side of the light bar (on your device or in the app). By default, the levels are set to +6º for warming and -10º for cooling. If you've adjusted the temperature levels on your own, the setpoints will move to match the last setting you chose.
For example, let's say you set your warming level to +12º and your cooling to -11º. The next time you open the app, the dial will show tick marks labeled +12º and -11º, and you can get right to those temperature levels with a single click/single tap.