According to The Japan News, the photograph was probably used as a reference for one of many statues honoring the dog.

As the story goes, Hachiko would wait outside the Tokyo train station every day for his master to return from work.

After his master died on the job and never came home, Hachiko continued to wait outside the train station every day for another 10 years, until he also died.

People who saw the dog were so moved by the heartbreaking vigil that the dog's name became synonymous with loyalty.

Read more here.