“When you see your best friend on Zoom, you don’t think, ‘OMG, a ghost,’ or ‘How did she get so tiny and inside my computer?’” says Amanda Shubert, teaching faculty at the University of Wisconsin–Madison and author of the new book “Seeing Things.” “The question my book asks is: When, how, and why did this experience of seeing things that are not there become part of daily life — a kind of illusion we enjoy, but are not tricked by?”