That was presumably when the station was used for cattle transport
sorted now thanks for diagram.Perhaps this diagram dated 1915 will help
View attachment 130441
To get from Duddeston top centre on the red (LNWR) line you would have to reverse somewhere between Proof House Junction and New Street Station then take the green (Midland) line at Grand Junction through St Andrews Junction and Bordesley Junction to get to bottom left at Small Heath on the yellow (GWR) line. Note this is a diagram not geographically accurate.
The building to the right is derelict. I wonder what plans there are for it - if any, other than demolition?
The gents is out of use by the look of it. I am sure some heritage centre would remove and restore it.
Those viaducts may become useful if we ever get HS2 as a link to Proof House Junction. Hope so.