The picture to the right shows a normal esophagus as it appears to the naked eye after it is cut open. The pearly white surface is the normal appearance of the esophagus which is lined by squamous cells.
The picture on the right is taken under the microscope. The area labeled "S" is how the squamous cells that line the esophagus appear under the microscope, whereas the area labeled "B" is the Barrett's metaplasia. The yellow arrows point to the "goblet" cells characteristic of Barrett's metaplasia.