Not much to work with, eh?
Though blocked by the rider's leg, the petrol tank does not seem to slope down at the rear, so not a 1912 frame or later. Nor does it have that faceted look of the 1910 petrol tanks, but this is stretching it a bit! The distance between the flywheel and the petrol tank seems a bit greater than the 1911 model D (or previous models), so I am guessing it is a 1911 model E, which had a new frame that lowered the engine. It was chain drive to a two-speed counter-shaft, thence belt drive to the rear wheel, no clutch or pedaling gear (the absence of the later permitted footboards to be fitted, which this seems to have.) The only other model available in 1911 was the F, a ladies frame which is quite unmistakable.
Yes, no?
-Doug