I think the short siding opposite the signal box would work for a coal merchant's yard with staithes.
What you effectively have is a platform with run round loop opposite. Typical, I think of a country terminus. The single facing platform would have been used for everything (passengers, parcels and light freight).
The siding (bottom left) will be needed to access the coal yard but could also house the premises of a local industry e.g. Small timber yard or builders merchant possibly.
Quite a big area to fill in scenically on the left.
Could be largely urban or possibly very rural