I know. The square LED indicator above the signal is called as theatre route indicator.
In some cases, especially for home signals at stations that have many platforms, or at routing signals guarding approach to a lot of diverging routes, a theatre route indicator may be provided. This usually indicates the route (or road as it is sometimes termed) with a numeric display. For example, if it shows 10,then the train will pass through the road number or track number.10 to stop or skip the station.