This sequence exposes one of the weaknesses in the story, one which Disney inherited from the original book. In a story where a fox and a cricket speak, you've got to really be obvious to let the audience know that the donkeys aren't supposed to and that those that can still speak started out as boys.
Alexander is the only character in the Pleasure Island sequence outside of Pinocchio, Lampwick, the Coachman and Jiminy who has dialogue. Looking at him, I can't help but think of Tom Stoppard's play Rosencrantz and Guildenstern are Dead, which takes two minor characters from Hamlet and reimagines the play from their viewpoint, or The Wind Done Gone, a version of Gone With the Wind told from the viewpoint of Scarlett O'Hara's mulatto half sister. You could make a whole other film that was Alexander's story, leading up to Pleasure Island and even following his life as a donkey.
When I upload the next sequence, you'll see that this sequence is numbered in such a way to suggest that it originally followed Lampwick's transformation into a donkey. It's interesting that they felt the need to reveal this to Jiminy before Pinocchio experiences it. Maybe it was a way of preparing the children in the audience for what is the most terrifying sequence in all of Disney. Or maybe Jiminy's discovery coming after Lampwick's transformation would be an anti-climax.
Woolie Reitherman takes over Jiminy. His work isn't as crisp as the other animators who have handled the character earlier. Eric Larson, known for his animal animation, is responsible for the best donkey shots. He certainly evokes sympathy for the donkeys. Charles Nichols continues with the coachman. It's interesting to see Bill Shull here, taking some donkey shots, as he usually was Tytla's assistant and animated scenes on Tytla sequences.