Why does Mollie defect?

Mollie

The white mare that draws Mr. Jones’s trap. Her personality is superficial and adolescent. For example, when she arrives at the big meeting in Chapter 1, Orwell writes, “Mollie … Came mincing daintily in, chewing a lump of sugar. She took a place near the front and began flirting her white mane, hoping to draw attention to the red ribbons it was plaited with” (27). Mollie is the only animal not to fight in the Battle of the Cowshed, instead hiding in her stall. She eventually flees the farm and is last seen, bedecked in ribbons, eating sugar and letting her new owner stroke her nose. Mollie represents the class of nobles who, unwilling to conform to the new regime, fled Russia after the Revolution.