Is it an Indian 340B, behind ? The Norton is earlyish wartime as it doesn't have the oil tell-tale on the timing cover.It has the 'AA Box' sidecar as used by the CMP for road-signage duties. Quite a substantial number of the WD Big 4s had the cargo body rather than the passenger variant. 'GLM' was issued in London from October 1941. The other outfit looks like 'GLA' - Also London and used from August 1941.
Definitely an Indian 340 (Chief) in the background, but judging by the civy rear light and black handlebar, I'd say it's one of the canceled French CAV models. 5000 were ordered by the French government in gloss green, black and chrome. When Paris fell 325 were re-alocated to UK.
The Germans ended up with lots of them. Ron