An almost biblical scene; and how did she get up there in that skirt!? She can't be very stable, standing on the sprung seats of a motorcycle, in high heels, with the main stand of the bike in the mud of an orchard...
The motorcycle is a 1926 Model 16H Norton. The Enfield drum rear brake was first used on the 16H in 1926 but in that year the 16H still used a combined oil- and petrol tank and lacked an automatic oilpump.