Who: If we could zoom in close enough to see anyone, there's a better than average chance they'd be Scottish! Typing up the Jurors Lists certainly gives that impression (check out the names from the 'Quarry Bay' district ), and other snippets confirm the area's large Scottish community:
- In 1925 Hong Kong had five British-only Scout Troops, one of which was the "Taikoo Scottish" troop. 
- In the 1930s, many of the congregation at Union Church on Kennedy Road were Scottish workers from Taikoo Docks. 
What was the link with Scotland? Jardines have a clear Scottish Heritage, but Quarry Bay was Swire's land and their roots are in north England: Yorkshire via Liverpool.  Any suggestions?
The photographer is another mystery. The only clue to their identity is a handwritten caption 'Hong Kong Harbour' on one photo. The generic comment suggests they didn't know the area well, and so were new to Hong Kong. Most people would arrive by ship in those days, and would pass by here on their way into the harbour. An arriving tourist taking photos from a liner perhaps?
Where: We're looking south from the ship towards North Point and Quarry Bay. Here's a Google satellite view of the area (I'll explain the grey section in a moment), flipped 180-degrees to match the photo.
I've noted three landmarks we can see along the photo's skyline:
- A - Mount Parker (the peak at the 'u' in the photo's watermark)
- B - Quarry Gap (the cut near the 'o')
- C - Mount Butler (the peak between 'o' and ',')
What: Most of the area you can see was part of Swire's business empire.
On the right there's a long building up the hillside, Braemar Terrace. (A Scottish name again!) I don't know if it was owned by Swire, but a 1942 year-book lists it as the mailing address for the "Engineer-in-Charge, Taikoo Sugar Refining Co., Ltd." 
(Does anyone recognise the individual buildings on the seafront below it?)
There's another small building a little way up the hillside under the 'o' of the 'Gwulo' watermark. I think that's the Quarry Bay Junior School, where children of Taikoo's workers went to school.
The buildings along the shoreline in the centre of the photo are the Taikoo Sugar Refinery, roughly the area of today's Taikoo Place. The only reminder left is the streetname 'Tong Chong Street'. Its literal translation is 'Sugar Factory Street'.
Over on the left are another couple of buildings up on a hill. They're on top of the ridge known as Korn Hill. The buildings were housing for Taikoo staff, and one of those staff, Mr Ferdinand Korn, gave the hill its name. The name lives on as today's Kornhill estate, but the old houses (and most of the hill!) are gone. Here's how they used to look:
Then we don't get a very good view of it in this photo, but the shoreline in front of Korn Hill housed the other big Swire operation in the area, the Taikoo Dockyards:
The final 'what' for this photo is my guess at the reason the area appealed to Swire. You can see that the area behind the refinery is a valley. There's a lovely walk around it (the Hong Pak Country Trail) that gives a very clear feeling you're walking around the edge of a bowl. That bowl is a great way to catch rain and feed it to housing / industry at the mouth of the valley. The grey area on the satellite view above shows just how large the water catchment is.
A good water supply was a big problem in Hong Kong for many years. I believe the sight of this catchment may have been the draw for Swire to build here. They certainly made the most of the resource, laying concrete channels along the hillsides to catch all the runoff, and building a string of reservoirs near the mouth of the valley.
The reservoirs are long gone, but you'll still see many of the small water channels as you hike the area, feeding into a large concrete channel that runs down the centre of the valley:
When: The seller described it as 'c.1940'. Can anyone confirm? Braemar Terrace has dark areas and light, almost like the camouflage applied by the Japanese to certain buildings during their occupation. That would date this photo to post-war.
Other: This started out as two photos. I've scanned and stitched them together on the computer.
Any more information you can share about the area is very welcome,
- Jurors list: http://gwulo.com/jurors-list-1908
- Scout troops: http://www.scout.org.hk/article_attach/12248/hks303-p13.pdf
- Union Church: http://gwulo.com/union-church
- Swire history: http://www.swire.com/eng/about/history.htm
- 'Braemar Terrace' in Google Books: http://www.google.com.hk/search?hl=en&safe=off&client=firefox-a&hs=qiT&r...