The Queen's Octahedron ship is essentially v2.0 of Donatra's ship in Khitomer Space, with much harsher penalties.
With Donatra's ship, it only cloaks and fires its Thalaron cone when the aggro target gets within 5km. So escorts can still go full dps on her without any serious penalty. In this case, a tanking cruiser is purely optional.
With the Queen's ship, any ship that gets within 5km is quickly fried. Besides that, she constantly pounds on the aggro target. This time, escorts should not go full dps and grab aggro because the queen will simply destroy the ship. Finally, an encounter where a high treat tanking cruiser is absolutely need to grab the queen's attention AND absorb her formidable arsenal.