Looking glass is an old English term for mirror (think mirror), Q has acces to the the Looking Glass Project at facility S4 at Area 51.
"Level 2 or “4-2” was known as “Alice’s Floor”. This specific floor contained a laboratory for weapons research and development, three board rooms, and provisions for emergency supplies. Also located on level 4-2 were two specific areas which contained components for project sidekick. Level 4-2 was also the location of Project Looking Glass. This device utilized six (composite) electromagnetic fields, and a height adjustable rotating cylinder which is injected with a specific type of gas. The entire assembly can be rotated 90 degrees from the horizontal axis. This allows scientists to warp the local fabric of space-time both forward or backwards by long or short distances relative to the present time. The Project Looking Glass device was used to predict the potential probability of future events. Once the device is tuned properly, images of probable future events are projected in open space within the fields, similar to a hologram. "
(Alice In Wonderland) (Future proves past)
https://www.thelivingmoon.com/42stargate/03files/Project_Looking_Glass_LANL.html