Tyne and Wear Metro signalling question

[Kryten2340]

This has been bugging me for a while but in the image below taken at Regent Centre, the signal at the 'wrong end' of the Airport bound platform has two route indicators and a shunt signal.

I know the route indicator at 10 o'clock is for the odd occasion trains terminate at the Airport bound Platform and use the cross over to the east end of the station to head back towards the city centre but what is the difference between the route indicator at 9 o'clock and the shunt signal. Is the route indicator for the avoiding line and the shunt signal for the depot or is it just a case of having two signals that serve the same purpose?

There is a similar signal just before Jesmond where the line to Manors diverges if I'm not mistaken.

 

[edwin_m]

The subsidiary aspect being on the main post with no offset probably means there is more than one subsidiary route, and the main junction indicator may be used to indicate the subsidiary routes too.

Is there another main signal on the entry into the depot? Probably a fixed red with subsidiary aspect. If so the main proceed aspect on the signal in the photo will light for a clear route up to this depot entry signal, but if there is a train blocking the route only the subsidiary aspect will light.