The mystery ship is the paddle steamer Snowdon (2), operated by the Snowdon Passenger Steamship Company Limited. The SPSC was taken over by the New North Wales Steam Ship Company (NNWSS) in 1899, a company formed by the Fairfield Shipbuilding Company of Govan, Glasgow in 1890. She was built by Lairds of Birkenhead in 1892 and was fitted with compound diagonal machinery.
The 338gt vessel was mainly used for excursions from Liverpool to North Wales, sometimes going as far as Blackpool. During World War I she saw service as a minesweeper operating out of Harwich and Dover, returning to the passenger service for which she was built in 1920.
The photograph is probably of Snowdon approaching the North Wales resort of Llandudno on a service from Liverpool. She was eventually broken up in 1931.
Harry CameronWorcester