That "looked like a yard sale" comment would sting, but she was probably right about the clutter part. I had the same issue at my shop and what fixed it was facing out fewer books with more space between them. I went to 12 or so on a grid, all covers out, nothing stacked or leaning, and the difference was night and day. People slowed down on the sidewalk instead of walking past, and I started getting way more "oh I saw that in your window" comments at the counter. The tighter layout also made it easier to swap books in and out, so the window stayed fresh without me spending all morning on it.