This fountain is fairly near to where I live.
The stone was donated by Queen Victoria is granite and commemorates Queen Victoria’s Diamond Jubilee. Clive of India (Major-General Robert Clive, 1st Baron Clive, KB MP FRS (25 September 1725 – 22 November 1774) built Claremont mansion which later became a royal residence used by Queen Victoria.
Queen Victoria lent Claremont to the exiled French King Louis-Philippe and his consort Queen Marie-Amelie after the revolution of 1848. Prince Leopold of Saxe-Coburg lived there until he became King of the Belgians.
So I think we can assume that Queen Victoria knew Esher quite well and thus the drinking was erected and takes the form of a statue of Britannia with a plaque of Victoria on the base.