Anime is just like peanut butter. Anime and manga styles can be smooth and homogeneous, which can be either really effective or really boring. Other times, Anime mixes styles such as serious art with super deformed character takes or different animation styles which can sometimes lead to interesting effects, and other times, painful jarring. Like peanut butter, good product depends on good ingredients, and in good proportions. Let's go into the fine details on our recipes.
When I say smooth anime (or manga), I am referring to anime that is consistent in style, tone, animation quality, and direction. Typically this is a good thing because consistency leads to reinforcing elements. For example, in the manga SANCTUARY, the art style and the backgrounds are generally drawn in Ikegami Ryoichi's photo-realistic style. This lends an air of realism that makes the gritty mob & politics story more realistic. A different kind of nut (i.e. art style) would have made the exact same story a different type of peanut butter. Amano Yoshitaka's version of SANCTUARY would have been beautiful, but his fantastic art style probably would not have allowed most readers to take the story seriously. Likewise Takahashi Rumiko's art style would have had most people searching for the punchlines.
However, just like in peanut butter, smooth can get to be pretty boring. For example, THE TALE OF GENJI supposedly captures the feel of the classic Japanese epic, but the ultra ssslowww pacing is deadly boring. Another example would be the explosion scenes in many American animation projects where the paint scheme rigidly adheres to the color chart and the debris and smoke smoothly curl away from the epicenter of the blast. Where's the impact in that?
Anime address this issue by introducing jarring elements, or, if you will, chunks, that jar you from complacency and grab your attention. By adding backlight flash frames, and/or alternating single frames of black and white, the explosions assault your optic nerve with a variety of impulses that cause more of an impact on your brain. Normally these effects are not visible except through frame by frame viewing, but the brain will process this effect as the visual equivalent of an impact. Chunky for a reason: effect.
Another effect that adds that special chunky flavor is when speed lines are added to the art. Occasionally, lines are added to the illustration to give the impression of speed. While this is a standard effect in manga, which is motionless, this technique has often been translated to animation as a cheat to reduce the amount of work (check out the flying kicks in most anime). However, even high quality animation uses this technique for many extreme motions. This method to deform the lines and colors of the art blurs the image to the eye and mimics the effect we see in real life. This effect is by no means strictly for the Japanese, Disney's animators have also used this effect in many of their films, although it has been almost exclusively applied to character motion.