You see how the aircraft placed sideway are also illuminated by daylight? That's because they are in the immediately vicinity of the hangar doors. All other aircraft have to be parked straight. That's how they are pushed into place.
Also, aircraft are last in first out, and since only the last aircraft has extra space to maneuver, that also means existing aircraft can't change position
Not really accurate. I have been on the hangar deck numerous times. And there is a whole lot of "it depends" that happens. What exists is process and places where airborne assets (planes, helicopters, etc) can be and where they cannot.
During flight ops in nice weather in non wartime, you will find a lot of aircraft on the upper deck, which frees up the hangar deck and it appears a bit more orderly. During weapons ops when an adversary is expected, that upper deck will only have assets that are expected to be deployed and the lower deck gets a lot more crowded. During resupply, the hangar deck may get emptied in certain areas, because the supplies land there for disbursement. During inclement weather, everything possible gets shoved in that deck and its a game of maximize space and things get pushed in at all kinds of angles to make that happen.
Its also not last in first out. Every asset goes through a triage process to understand its state. Aircraft that have more severe issues where the parts are scarce ,or not available, or its not repairable at all, those get pushed into places where they provide the least amount of interference. If they are awaiting a part coming in on a resupply aircraft, it might get pushed into a different area.
Things are constantly moved in a hangar deck. Probably the most accurate thing that can be said is that those assets that are needed and ready to go are closest to the elevators.