The Trains on Railway Parcel Stamps & Railway Letter Stamps of the World pages of the Aphabetilately website includes a picture of a 1923 issue of a 2 paisa railway parcel stamp from the railway to Darulaman. A paisa was a subbdivison of the Afghan rupee used in the 1920s.
The stamp is described as “small quantity issued, no used copies seen”, citing page 29 of Patterson, presumably Afghanistan: Its Twentieth Century Postal Issues by Frank E Patterson III (New York; The Collectors Club, 1964).
The logo is the national emblem of Afghanistan, first used during the reign of King Amanullah and now in the centre of the current national flag. It shows a mosque, with the mihrab (the niche indicating the direction of Mecca) and a minbar (pulpit), with a royal shako (hat) above. The rays forming eight points were inspired by the 19th century Ottoman Imperial standards, and the shape changed from a circle to an oval in 1921, according to the Afghanistan 1919-1928 section of the Flags Of The World website.