At clock out each shift is checked against your attendance rules. The possible exceptions are: Clocked in outside the depot geofence; Clocked out outside the depot geofence; Required photo missing; Clocked out after the reminder time; Required break not taken; Odometer end reading is lower than the start; Shift longer than the maximum hours; Pre-start checklist had failed items.
A shift with no exceptions is approved automatically when that setting is on. A shift with one or more is Submitted and waits in Attendance, Needs review; the dashboard counts them under "Shifts to approve".