Perhaps it's related to the story or plot. Maybe the big right arm has some special power or significance that will be revealed later in the cartoon.
It could be part of the cartoon's style or to emphasize a certain trait or ability of the skeleton. Sometimes, artistic choices like this are made to catch the viewers' attention and make the character more memorable.
Maybe it's for a visual effect to make the character stand out or add some uniqueness.
This is a rather odd and inappropriate topic. Usually, such scenarios in cartoons are not based on normal or healthy circumstances.
Maybe it's due to the style of the cartoon. Some cartoonists choose to simplify the arms for a particular look or to focus on other elements.
There might be a few reasons. Maybe the artist wanted to focus on other aspects of the character or the scene. Or it could be that the story doesn't call for a display of physical power through arm flexing.
Maybe it's to draw attention or create a sense of mystery. Sometimes, artists do it for visual effect.
One possible fanfiction could be about Naruto's right arm gaining a new and mysterious power. Maybe it starts to glow with an unknown chakra, and he has to figure out how to control it without losing himself. It could be a power that has a connection to an ancient ninja clan's secret technique.
Perhaps it's to show some sort of conflict or interaction. Maybe the guy did something that made the cartoon character react that way.
It could be a cartoon character with a unique physical trait. Maybe it's a superhero with one arm enhanced for special powers or a funny creature with an odd body structure.
It could be for creating a unique or shock value moment. Maybe it's part of a fantasy or horror-themed story.
His right arm could get a cool tattoo that gives him extra powers. For instance, a tattoo that allows him to summon a special type of animal or use a unique jutsu.
It could be for a fantasy or magical scene. Transparency and money dropping might add an element of surprise or mystery.