The SkyPriority checkin area leads to the SkyPriority security check. The SkyPriority security check is the only location with PreCheck so you will have to wait in line until getting to the BP checker - if they scan and you get the 3 beeps you are sent to the PreCheck line, if not you are sent to the regulair SkyPriority security check.
Hijacking a bit because I don't know enough about this topic: I've only recently gotten Global Entry and haven't had a PreCheck-eligible flight yet - what happens if you aren't SkyPriority and it doesn't beep three times for PreCheck? Or what if you're flying on a different carrier?