Again, you are offering ways that photography can be a useful means to an end that we previously accept as good for other reasons, not ways that photography can be a good in itself. Suppose the humans were already extinct; would you then consider it a good in itself for machines to be taking and interpreting photos? Would you set up a video camera with a solar panel in a park, endlessly taking 60 photos per second, then deleting them, because photography is good even if nobody looks at it and it produces nothing else outside of itself?
I am fond of the humans and so I would like them to survive, but only because that is a means for them to be conscious, at least in some cases.
A legacy that lives past humanity seems better than one that does not. If something views or does not view that legacy is effectively irrelevant as humans would never know.
PS: As to your final central point, some feel keeping a loved one alive even if they never recover consciousness is a net good.