Camera obscura in Hughtown

The old windmill at Hughtown in the Isles of Scilly has been turned into a camera obscura. When it is working, the apparatus pokes up through the roof. Notice that there is a window on this side of the camera apparatus. Here's what it looks like from the inside looking up

It looks like light is coming straight down vertically. So what must be happening is that light enters through the horizontal window and is sent downwards by a mirror. It passes through a lens to focus it and then you get a live image of the town projected onto the table.

It's fascinating and so much better than the pinhole cameras that I make sometimes. https://en.wikipedia.org/wiki/Camera_obscura says the size of window should be 1/100th the distance from window to screen. Distance to screen might be about 3 metres so a 3cm window would work. I hadn't realised you could get away with bigger than a pinhole if the projection distance was bigger.