The Miniature Schnauzer is supposed to be ear cropped according to the American Kennel Club breed standard. You can still show a dog that’s uncropped, but it is usually easier to show a dog that is cropped. The ears does change the appearance of the dog quite a bit as seen on the picture above. The two mini scnauzers in the picture are the same age, but clearly shows the difference with or without cropped ears (the miniature schnauzer on the left has natural (uncropped ears), then one on the right has cropped ears). To read more about how to tape the cropped ears to train them to stand, read this article.