Diana Bloom from the American state of Virginia posted a photo on Twitter last week that is getting a lot of attention right now. It has thousands of likes and re-tweets. The photo shows one page of her high school yearbook. In the United States, high schools and universities put out a yearbook at the end of each school year. The book is a way to remember the school year. Yearbooks usually have photos of all the students, teachers and staff members. They include photos of sports teams, clubs, special events and other important moments. Often, when a person grows up to be famous, their yearbook photos are used to show they were once a normal high school student. But the Stafford High School yearbook is already special. It includes the photo of Alpha Schalk. Why is the photo getting so much attention? Alpha Schalk is a dog. Alpha belongs to Stafford High student Andrew Schalk. Alpha helps Andrew remember to take medicine for a disease called diabetes.