What is this tweet tunnel?

The tweet tunnel is a way to quickly view a sequence of tweets, each appearing to scroll up vertically on top of the other, as if viewing them via mobile phone scroll on the timeline while reading Twitter updates. These 'tunnels' of fast text, usually formatted within quotes with some introductory comment above them, spread on social media like Tumblr, Facebook, Reddit to showcase what a person tweeted in a succinct manner that requires one to 'click and scroll' only when further context might be appreciated on a specific tweet among the tunnel.

It should be noted that these can be highly inaccurate or outright fabrications in some cases, so taking tweet tunnels at face value without investigating any of the included claims is ill-advised.