The driver is obscuring the cab number so the engine cannot be identified. There are no lamps on tender and fireman is missing, so with think the train has just arrived from the north (from Hamilton?) and he is uncoupling the engine for a run round.
A charming local scene with a Jumbo on a local at Lesmahagow station in Lanarkshire during the 1950s. A springtime photograph as daffodils can be seen.

© David P Williams Archive / Rail-Online