The Cooling Quality result indicates this area of the part has a cooling time variance which is lower than normal.
The Cooling Quality analysis calculates the entire time that is needed for all areas of the part to completely cool, and plots variations from that time value. When a result indicates that an area has a lower cool time than normal, that area will cool before other areas of the part. This area of the part would require less cooling than other areas, and is a potential source of short shots or hesitation.
When the cooling time variant is lower than normal, it can also indicate that you have big thickness variations in your part and that you should consider moving the gate into thinner rather than thicker areas.