So, we get a lot of suggestions for the general idea of being able to turn the image spoilers (the "spoiler" and "nsfw" images hiding the actual images) on and off – for example, here, and here.
The thing is, as said in the thread, these systems will not work. To explain why, here is James from 2 years ago, speaking in the council on this very topic.
There’s just too much involved in making separate cached copies of each gallery and its various configurations for each individual user and would slow down the site for the hardware that we have available…
User 1 with the view X checked would see a gallery without any X thumbnails but would see Y thumbnails, User 2 with view X and view Y checked would see a gallery without either of those thumbnails, User 3 with view Y checked would see a gallery without any Y thumbnails but would see X thumbnails, etc.
There are 220k+ users and 10k+ galleries each containing numerous sorting options and pages. Each one of those possibilities would have to be cached separately instead of how it works right now where everyone sees the same thing and only private stuff like dashboards are customized to the user.
So, this is a PSA: Please, stop asking for the ability to turn NSFW and Spoiler on and off.