Mrs. Whynnes doesn't flinch when the cobra crawls across her foot. This is ironic because it was thought at the time that women get scared at everything and they don't have a lot of self control.
Everyone thinks that the American kept control, but in reality, Mrs. Whynnes was the one who kept control. This is ironic because it proved the point of the colonel and switched quickly over to proving the young girls' point.
The theme of this story is that you can't judge how brave, calm, or courageous someone is based on their gender. Women were thought to have very low self-control and get scared at the smallest things at the time. As shown in this story, Mrs. Whynnes kept perfect self-control when the cobra crawled across her foot.