Riot86 wrote...
After my thoughts on some similarities I found between parts of the Citadel and Cronos Station as well as the Satellite dish from Projekt Overlord (if you are interested - my post can be found here: social.bioware.com/forum/1/topic/355/index/12047832/581#12474519) I'd like to share some of my thoughts on the idea most of "Priority: Earth" being a hallucination.
I hope I'll get lucky again and can contribute something useful and new 
So, in this thread some people thought about the possibility that not only the part after Harbingers beam takes place in Shepards head, but in fact the majority of "Priority: Earth".
If this should be the case, I would assume that much like the Citadel in the ending, London might contain elements from Shepard's memory. So I kept my eyes out to spot something familiar.
And I actually believe I found 2 things, which reminded me A LOT of places I visited earlier in the game.
1.) Is this Earth or Menae?
After taking out the AA Battery, you'll find yourself in the Forward Operating Base. A place which I felt was a little too peaceful with all the fighting going on just a few blocks away. I can't describe it in better words, but I just got the feeling something was "off".

But for some reason, the atmosphere and even the base itself seemed very familiar to me.
I was almost certain I had the same feeling of "nothing is happening here" with a war raging on just outside before - in the turian base on Menae during "Priority: Palavan" in fact.

So, I tried to find some similarities between them. This is what I gathered:
- As stated above, the mood in both encampments was actually kinda peacefull given the circumstances
- On the right side of each base, you find a communication terminal (in London used to contact your ME 2 Squadmates, on Menae used by General Corinthus to contact Palavan)
- In the middle of each base is a turret in an elevated position
- Which you have to use in both cases to defend the base against Husks and Cannibals
- Even the provisorily lamp posts are absolut identical (though this in fact could really be a case of reused assets)
- And surprisingly Primarch Victus is in London, too (Shep himself wonders why he is there), which even further establishes a connection to the mission on Menae
Oh, and remember the briefing with Anderson and Coates?

Looks a bit like this, if you ask me...

2.) Is this London or Vancouver?
After you got your briefing from Captain Anderson, the push to the Conduit begins. For me, this is the moment where "Priority: Earth" actually starts, as this is the final assault.
So, after fighting some Reaper troops you'll end up in a parking lot. Via a ladder you enter the first buidling in this part of the mission. And then you come across this door...

The moment I saw the husk I immediately thought of the beginning of the game. For those who can't remember, while fleeing from Vancouver in the first building you enter you come across a door, were the exact same thing happens to you.

And to be honest, I couldn't remember another instance, where a Husk attacked you through a half opened door like this in Mass Effect 3.
But what happens after this in Vancouver? Well, of course it is time for our favourite little boy to appear in a ventilation duct to the left.

So naturally, after getting attacked by a Husk in London in the exact same fashion I took a look to the left as well.

And there was an airduct, too.
But that's not all - right beside the airduct is a console which can be interacted with. And on it, you'll find a message of a boy who tried to contact his parents. That's another nice coincident, isnt it? 
Also, Vancouver is the last time you saw Anderson in person before London. So, after meeting him again in London there is a deja-vu like this for now reason whatsoever?
Oh, and in both cases you use a ladder moments before you reach set door. Which is another strange similarity.
Of course, this is no proof that these part of "Priority: Earth" take place in Shepards head. I'm still not 100% sure myself whether to think this part is real or just a hallucination. But at least I think I can say now, that there are indeed some strange things going on in London
So, what do you think? Are there any resemblences? And if there are, are they intended or just coincidences? 
Damn.