The photo above is simply a tight crop of the photo below. Almost certainly taken to show the new Northcote loop connection (opened Nov 28 1904) that allowed Whittlesea line trains to go direct to Princes Bridge instead of via Royal Park we see an up Whittlesea train departing Merri station. Electrification would come in July 31 1921 and Rushall station would be opened on Jan 1 1927.
This photo had caused much puzzlement for me. The up signal behind the guards van shows 2 arms with the bottom arm at proceed. As Merri had no signalbox at this time that ruled out the possibility that it was a starting and distant signal on the same post. Recent perusal of the interlocking register has uncovered an amazing fact that the signal behind the guards van is described as a "repeating home signal" which repeated the indications of the home signal seen at the left of the picture. The "repeating home signal" was 310 yards before the home signal it repeated. This is the only known example of a "repeating home signal"