The Vickers Mk.VI was designed as a fully tracked reconnaissance vehicle armed with .303 and .50 Vickers machine guns. The Mk.VIB had the same armament but had a rounded cupola. The one in this photo obviously has something larger than a .50 machine gun for its main armament.
Vickers Light Tank Mk. VIB
The British produced thousands of these light tanks between the world wars, and some were used by the Egyptian Army during the War of Independence in 1948. This tank was halted near a chicken coop by defenders of Kibbutz Mordechai.