E.T.W.Dennis of Scarborough issued postcards from 1894 and would appear to be have been the first to publish a British pictorial card - the firm closed in 2000.
These Manx cards would appear to date from 1898 and are on undivided backs as required for pre 1902 cards.
The pictorial side was arranged vertically with a high quality image taking up the upper third of the card, the rest was blank space for the message, as at the time of issue the address only could be written on the reverse side.
Webber claims that Dennis took the photographs himself, though my Port Erin card has an obscured earlier lettering on the photo with number 8043 visible - there are several more Manx views in this series - Castletown, Douglas from Douglas Head, Groudle Glen, Kirk Braddan, Laxey Glen Gardens, Peel Castle & Harbour, Port St Mary, Ramsey from Mooragh Park, Ramsey from South - all standard tourist views.
I have three such cards, two posted 1902/3 from England but presumably bought on the Island, the other of Peel also posted Douglas.1902.
Unlike Valentine's Cards they were not numbered. Many later E.T.W. Dennis's views were used in the Edwardian Albums including 160 Views.
Later issues by the company were generally under the Dainty Series label.
see </ http://www.guernsey.net/~gtwebber/ >for a detailed discussion re ETWD and the early cards issued.