

It’s a very good question - though the 1870s is about when “dry plate” photography was introduced, and during the decade, exposure time potentially dropped below a second (depending on the what/where/how of the photograph).
Roughly 1850-1860ish is when you’re looking at over ten or twenty seconds for a photo, which is probably a “cat sitting still” limit. Earlier than that you start going towards minutes and hours for a photograph. I think there are cat photos from the 1840s, though I imagine the photos are blurry or the cats are asleep
If you want a bunch of early cat photos to look at, in the UK, there was a cat photographer, Henry/Harry Pointer, who was seemingly pretty well established in the 1870s. Photohistory Sussex - Henry Pointer (scroll down to the “Brighton Cats” bit)










It depends exactly how you’re sharing things - I use “pCloud” for online storage, which allows sharing links to files and folders.
You can either share folders of things which can be previewed/downloaded within the pcloud website, or put them in the “public folder” which should allow direct linking to the files. It has no comments/social media style stuff tacked on - just files.
Their servers are in Switzerland, and they are considered to have good privacy.
However, they’re not open and it does cost money.
You can pay a one-off payment instead of monthly etc, if that makes a difference. I think when I got mine it was something like £200 for 2TB permanently, though that was quite some years ago now.
Note that they appear to be in a perpetual state of “special offer! 50% off!”, though the discount varies, I think it’s probably never “full price” - but if they’re presenting the price as “unmissable, limited time only”, I assure that it is “missable”.