Death of a beloved character often makes a cartoon story sad. For example, in some stories, a cute puppy might die, leaving all the other characters and the viewers heartbroken.
They are. Edits in comic books could range from color adjustments to reworking dialogues or adding/removing panels to better suit the overall theme and flow.
Once there was a sad dog in a cartoon. The dog was left alone in an old house when his family moved away. He waited day after day for them to come back, sitting by the window with a forlorn look. His little tail that used to wag so happily now just hung limply. Every time he heard a car pass by, he hoped it was his family. But as days turned into weeks, his hope started to fade and he became more and more sad.
Loss is a common theme. For example, in 'The Lion King', Simba loses his father, which is a very sad moment. It makes him grow up in a difficult situation and has to face the reality of his father's death.
The movie "Up" has a very sad beginning. Carl and Ellie meet as children, both with a passion for adventure. They grow up, get married, and save up for their dream trip to Paradise Falls. But life keeps getting in the way, and Ellie becomes ill and passes away. Carl is left alone with his memories, which is a very touching and sad part of the otherwise adventurous story.
Loss is a common theme. For example, in "The Fox and the Hound", Tod and Copper's friendship is threatened by the fact that they are supposed to be enemies due to their species. They lose the innocence of their early friendship as they grow up, which is quite sad.
One cartoon sad story could be about a little kitten who got lost. It wandered the big city all alone, with rain pouring down on it. The kitten missed its warm home and its owner terribly. It meowed sadly as it searched for a familiar face or place, but everywhere was strange and cold.
Well, for copy editing a novel, you need to focus on language accuracy. That means correcting punctuation, fixing word usage, and ensuring the sentences are structured properly. Another important aspect is to maintain the author's voice while improving the clarity and flow of the text.