The Citadel had been, for most part, rebuilt from it's past. After the events that destroyed the Reapers, turning the once central hub of galatic life, into a Crucible. A weapon forged by the ancient race of Protheans that wiped out artificial intelligence throughout the universe, taking along the reapers with it. The Citadel became a husk of it's former self, a derelict relic suspended in the middle of the Serpent Nebula.
It took several generations and decades of combined effort from the Council races to terraform, once they relocated it, and rebuild it to the semblance of civillization we see today.
As the humans looked out the many glass walls around the room, they could see pockets of the Presidium under the holographic sky that kept the atmosphere in. Buildings, offices and various structures dotted the landscape, many of which are a mix of the past with the present built upon in. Such as the Huerta Memorial Hospital, architecturally preserved by the Council for historical purposes and only ever so slightly renovated. To this day it remains as a functioning facility and as a keepsake of our history, standing tall in the complex, reminding all who view it of the adversities they had to overcome to get to where they were today.
While surrounding it were many other completely new buildings, replacing those that were destroyed in the events that transgressed here.
And even though the living areas were sparsely populated as compared to before, due to it's still recent re-introduction as the hub of galactic life, the Citadel was still a beautiful place and growing in number day by day with ship that landed in it's docks. People could be seen sitting around the fountains, engaging in small talk with each other and going about their life.
"Good day. Captain Tyzurius, several Human Alliance ships have arrived at the Citadel space station through the Widow Mass Relay. The Council believes it to be the human ambassadors and prompts you to greet their arrival." A V.I., resembling a purple asari, blinked into existence above a nearby console, her mechanical voice expressed artificial cheer and her holographic limbs gestured and pointed in a way that would somehow make the dullest conversations bearable.
"I will, Avina." Tyzurius replied, nodding to the interface as he lifted his three digits off the console.
"I shall update the Council on your behalf." The V.I. then turned to few who wore the uniform of the SSV Normandy. "Welcome back to the Citadel." With a smile. "And thnk you for using Avina." Before the holographic image faded away to tend to the inquiries of another Volus tourist somewhere else.