Personally after the initial "oh wow Nova" my mind started blaring red warnings and reminded me of this preview's tagline...
And based on Orion's body language in this scene (sitting on the ground as if he just fell over and is taken aback by the sight in front of him)...
...my brain was like "I don't think that's OUR Nova. Nova would be a bit more restrained compared to this."
So yeah, I wouldn't be surprised if this is one of those "house is haunted and giving us illusions of our deepest desires" situations (basically the opposite of what went down in the Dark Arts test at Warthogs), and Orion's about to get a jumpscare once he lets his guard down.