This block instrument is the same as the ones used at Whitmore and the other boxes between Crewe and Stafford that I visited. Same as at Minshull Vernon (a few miles north of Crewe on the West Coast Main Line) which I also visited. There is a train approaching on the down line, shown by the black needle pointing to "Train on Line". This needle would be controlled by the signalman where the instrument is located. The red needle at the top shows the state of the needle at the box in advance on the up line.
Thanks to John Hinson for permission to show this photograph.