Jailer Intro Cinematic - Sepulcher of the First Ones Raid (Spoilers)

wowhead.com:

A special cinematic plays before the Jailer encounter in Sepulcher of the First Ones. Spoilers ahead! While previously part of the Jailer's intro was datamined, a crucial piece of the story was hidden until now.

As the camera zooms in and rotates around Zovaal, we see that he's looking at a globe of Azeroth, specifically Northrend. This location is significant as the expansion started with the veil between Shadowlands and Icecrown ruptured, and over the course of the expansion we learned the Jailer's role in creating the Lich King and Helm of Domination.

The pose is also reminiscent of Algalon the Observer, a constellar seeking to re-originate Azeroth and destroy all life as we know it, whom we faced in Ulduar with a similar celestial globe. Datamining ended here, but in today's cinematic, we see that the Jailer has reached into the Forge of Souls beneath Icecrown Citadel to harness the power of Azeroth, wounded and vulnerable after the events of Battle for Azeroth.