The theme of this story is very close related to the message of the text - not the person's appearance, but the inner world shows the real beauty of the person.
The composition is "in media rēs"- as if the readers already know this story. The text "The Birthday of the Infanta" can be divided into two parts: first one could be revelation of the Dwarf. When he sees his reflection in the mirror everything changes in his life. And the second part could be after the Dwarf's death. Little princesses became very sad, because there was nobody to make her laugh in her birthday.
Speaking about the climax, it appears at that moment when the Dwarf realizes that it was he who was misshapen, hunchbacked, foul to look at the grotesque - he cannot take it and he dies.
"But the Dwarf never looked up, and his sobs grew fainter and fainter, and suddenly he gave a curious gasp, and clutched his side. And then he fell back again, and lay quite still. ..."
As to the characters of the story, I can say that they are very different.