Mr. Grove is shown going home, wheeling little Ernest in a baby carriage with the baby's favorite toy bunny visible. Later in the episode, Miss Mardle is shown with the toy bunny still in her possession at her home.
The real Harry Selfridge was born in 1858. By the end of the series 3, post First World War and the death of his wife Rose (1918), Selfridge would have been in his early 60s, yet Jeremy Pivens, in his late 40s, has not been aged accordingly.