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A few people commented on the possibility that the photograph described as fallen British soldiers actually portrays fallen German soldiers. Some thoughts on this 
https://twitter.com/SimonJHistorian/status/1292853156490219523
https://twitter.com/SimonJHistorian/status/1292853156490219523
Here's the thread in question: https://twitter.com/CarlaJeanStokes/status/1292835643072999424?s=20
Of course I think it's 100% possible that these are indeed German soldiers. I'm definitely NOT a uniforms expert (other than being able to recognize helmets in a crowd).
I think it definitely takes a community to describe a photograph - particularly one that was taken 100 years ago. Archival description is a big job for any institution (let alone one with millions of photographs in their archives).
Many organizations simply don't have the resources to thoroughly describe their holdings, or to return to those descriptions on a periodic basis to check for the need for revision. This includes heavy hitters like LAC in Canada.
In a perfect world, we'd have all the info we need to describe photographs. Even in a less perfect world, they'd pair a photographic materials expert (me) with a uniform expert (someone else) and someone with a meticulous knowledge of day-to-day FWW events (someone else else).
This level of person-power almost never happens. Some museums open themselves up to crowd-sourcing information, which is exactly what we're doing here.
But we have other tools at our disposal, including comparing John Warwick Brooke's other photographs portraying the fallen that were taken in the same set as the one I originally linked.
I'm going to post the links here, because as with the original in question, there isn't an option to download these, and I'm going to respect the @I_W_M decision to disallow that.
Regardless of the nationality of the fallen soldiers in the photograph - and I really wish the archival descriptions were as accurate as possible, AND I definitely strive for accuracy in my own work -
Much of what I said before remains true: the Brits normally didn't photograph their own dead; most nationalities followed that rule too; it was considered OK to photograph the wounded in certain situations; AND it's telling that only some photographs are available to download.
