How to View Hidden Content on Tumblr
As of this writing, Tumblr has permanently banned any adult NSFW (not safe for work) content so changing a setting in your Tumblr account to view adult content on Tumblr is absolutely pointless as any Tumblr blogs that contained adult content have been taken down and removed from Tumblr.
A free browser bookmarklet that reveals any hidden content on a Tumblr page.
CSS is what gives a web page its look and layout and there are two main directives that cause content on Tumblr to be hidden, display:none; and visibility:hidden;. For example if you view the source code on any Tumblr page and do a search (CTRL + F) for either of those two items, you will be able to see what things Tumblr.com is trying to keep hidden from its visitors. This free bookmarklet can be installed quickly and easily to any web browser and a single mouse click will remove all this formatting, exposing any and all hidden content on any Tumblr page.
Hidden Content Tumblr Blog Source Code
In addition, any items that Tumblr intended to hide from you will be outlined with a red triangle as shown in the image below. As you can also see from the images below that after clicking this bookmarklet to expose any Tumblr hidden content, the web page will instantly become completely unrecognizable as a Tumblr page because css is the glue that visually holds a web page together and this free bookmarklet removes all of that glue so you can see the web page complete raw, with all things exposed, including any items Tumblr tries to hide from you.
Tumblr Blog Before Expose Hidden Bookmarklet Clicked
Tumblr Blog After Expose Hidden Bookmarklet Clicked