Yesterday, the new farrier (Toni), commented that Izzy's attention span is roughly 20 minutes. She recommended working on that by asking her to focus for longer periods of time and gradually expanding what Izzy is capable of doing.
That seemed like sound advice as I reflected on it later. Then I realized something: my attention span is only about 20 minutes as well. That's why Izzy can only focus for that long.
Nuts. Yet again, Izzy problem comes from one of my weakest points.