I have looked everywhere, and can’t find a definitive answer on this one. On the left rear of a tiger, above the fender, there is a box that looks similar to a suitcase. What was it’s purpose?
For some reason I can’t link a picture, so a link to an image is shown below:
The track toolbox was originally strapped flat to the wall:
When the air filters were added, it was supported underneath them, on two inadequate metal arms:
Soon thereafter, a robust metal frame was introduced to hold it firmly. You can see the metal frame on your linked photo, which shows the Tiger at Bovington Museum, UK.
But the box on that tank is not an original.
The external toolbox frame was deleted from the Tiger’s design in October 1943.
My thanks to both of you! I suspected that could be it. I found that as an answer, but I also found ones saying that it was exterior communications equipment to talk to the commander, smoke canister storage, crew personal items, and small hand tools.