Finder Quick Look change

What has happened with Quick Look? I am going through dozens of photos and use Quick Look to see a large view of each image in order to choose which ones I want to open in Photoshop. JUST YESTERDAY, Quick Look brought up a large image that I could expand to fit my 27" display (or make smaller to see desktop folders it might cover). TODAY suddenly the Quick Look just gives me a rather small thumbnail of the photo—not much larger than what shows up in the Finder window in column view—on a grey background with the name of the file and other file info. The grey window can be resized, but nothing in the window (image, info type) changes size. Did something change overnight? Can I revert to the previous Quick Look and get the large preview of the image? I didn't change any settings as far as I know.

27" iMac (late 2015)

OS Monterey 12.1