(1) The blue line can be seen going across Jaune's hair.
(2) Sky Lark is out of uniform.
(3) Notice the non-colored character taking notes down on paper on the right in the row behind Cardin.
(3) Next to Lark one can still see the pencil in note-taking position, but its owner has vanished.
(3) The blacked-out character is back.
(4) A view of the Classroom showing Jaune's desk beside the desks of Blake and Pyrrha
(4) Note that Oobleck is in front of Jaune
(4) The scene changes to Jaune's perspective when speaking to Oobleck, but it also shows Blake and Pyrrha behind the professor