Update: Naka has posted some tweets which appear to give a little more insight into the altered photo:
It would seem that Naka is referring to the fallout surrounding the release of the much-derided Balan Wonderworld, which was created alongside Ohshima.
Original Story [Tue 5th Jul, 2022 21:30 BST]: Things are seemingly not well in the Balan Wonderworld world, as seemingly-ousted creator Yuji Naka has taken to Twitter with a rather passive-aggressive way of showing his displeasure.
Naka posted a photo of the NiGHTS team in celebration of the game's 26th anniversary, showing the original team who made the game, with one conspicuous absence: Naoto Ohshima, the creator of Sonic and Naka's co-worker, who was the character designer on Balan Wonderworld, and the vice president of Arzest, who co-developed Balan Wonderworld.
Or rather, it's not so much an absence of Ohshima, but a rather noticeable black lump where Ohshima used to be, as noted by a poster on ResetEra called MechaJackie.
Here's the photo itself:
Uh... thoughts? Let us know in the comments.