Some scenes aren't in the Gallery (for example the Tecbot ones), but the others should be there after seeing them. The Musa thing is somewhere in the background at a location (some have posted a screenshot here already it seems), check your items if you maybe picked it up already.
The one on the foot with Stella, the reward from the Trix, the two from Musa, neither the arrival of Bloom and Stella's mouth, none of these appear in the gallery even after seeing them.
