Mystery car

I think Ariejan Bos is right, or very close. The bow in the front axle is the most extreme that I can find, and it appears to be the same curvature. The next closest is probably the Panhard Levasseur's of the period, but it is consistently less bowed. The starting handles are also different. After that, shallow bows are everywhere, and continued for some time. The most distant house in the background has a covered veranda of a type that one associates with early 19th century seaside resorts, but the ironwork looks later.

To show that my suggestion for a Milnes-Daimler is not thin air, I uploaded an image of a 1903 16hp Milnes-Daimler. As you can see, 'below the girdle' the cars are very similar: the protection plate and crank handle, the dumb irons, the wheel hubs. The identical dark half circle behind the protection plate is probably the front axle (with deep bend) and front part of the engine. The curved tie-rod and the shape of the rear mudguard are minor and not essential differences. The mystery car has more oilers on the dashboard, but these numbers could differ by model and client preferences.
For the Rochet & Schneider/Martini suggestion there is no visible evidence and to be honest, the driver has no resemblance whatsoever with Captain Deasy.

The car doesn't have a registration number so the photo must have been taken before December 1903.

I had a feeling that the car might be a one-off built by the driver and financed by the other three men in the car. It looks to me to be of about 1903 from its' general arrangement with a wood and flitch plate chassis, chain drive and a large 4 cylinder engine. I can't place the design with any known manufacturer but someone may know better. The photo was taken in the UK.

Could this be Captain Henry Hugh Peter Deasy (an ex-military man and adventurer given to sporting moustaches and starched collars) in the passenger seat of his 1903 Swiss Rochet & Schneider about to drive from London to Glasgow for his demonstration run? Or maybe in his similar Martini, returned after being driven up the Rochers De Naye Cog-wheel Railway in Switzerland as a publicity stunt a little later that year? He had formed H. H. P. Deasy and Co to import both Rochet-Schneider and Martini cars into the UK in February 1903 and more or less took the whole business over by 1905. He lived in Kensington.

It would be interesting to know where the photo was taken. Victoria Terraces were all over the UK, but also in the New World. The car has a strong similarity with the 1902-1903 Mercedes or preferably the Milnes-Daimler, which was the UK-licensed version. Only the bonnet and the radiator differ: the original radiator was much smaller and could have been the cause of insufficient cooling. It would have been easy therefore to increase the cooling capacity by this replacement.

This is a toughy! Sign on the building I think is Victoria Terrace,,,,,, but that can mean anything and anywhere English is spoken. Looks like a rear entrance, chain drive, I'd say pre 1905......but from there, I can't even begin to figure it out. great photo though!