But he looked more like his Force Phantom self in the TLJ flashbacks than he does here. Unless he’s interacting or guiding Rey through visions similar to what she had involuntarily in TFA? The possible wrinkle here is everyone percieves Luke as they last saw him?
Is this just another Jedi Temple vision though since R2 is still there
The picture might not exactly match any scene that is in the movie. At least parts of the picture is directly taken from TLJ’s Ahch-To shoot, and the hair and beard matches Luke’s Ahch-To look. If it was supposed to be a flashback he would have the shorter dark beard. So if it is the Jedi Temple fire around him then he might not be there physically, but possibly as a “ghost of Christmas past” type of thing. But if it’s a different fire in the “present” then he could be there as a force ghost.