We know that expert chess players look at chess boards differently from novices, focusing on the most important areas; this paper shows how expert teachers do the same.
Experts focused on the blue squares; novices on the orange ones; novices were distracted by irrelevant visual stimuli (like a student’s colourful laces…)

How experts look (see?) is based on their knowledge of what might happen next:
…experts can ignore irrelevant information to focus on what matters.