Pokemon, from the very beginning, had no way to represent Pokemon, so the programmers used sprites. A sprite is a soda, but it’s also a term for a bunch of pixels formed to make a certain character, object, background, etc. For example, the trainer character that you control throughout the game is a sprite. They have changed throughout the years, and programmers for online Pokemon games use them for customization of your character when you play their games. The most notable sprites throughout the games are of Pokemon, whose appearances also change significantly throughout the games. Remember all of the Pokemon games when all you saw were static sprites, incapable of motion? This was changed throughout the games, going from static to a brief animation, then a full animation with the Pokemon Black and White versions.
The Pokedex also has different versions of the sprites. These sprites are kept by online databases dedicated to Pokemon, and also display a shiny sprite of the Pokemon, possible or not. Sprites for all characters exist, like Team Rocket, or Gym Leaders. If you’ve tried to play FireRed, LeafGreen, or any other GBA version with Team Rocket, you would have noticed their appearance changed significantly when you got to HeartGold or SoulSilver. That is because with time, comes change and improvement to the Pokemon series.
Gym Leaders that have looked pixely in the beginning now have been suited to a more pixel-friendly environment, where you can still see them and know that they are head of the gym. The people you may meet on your journey also change, like Hikers or Pokemon Breeders.
With time, more kinds of trainers were added to the game, and some even had their name revised to fit a more appropriate environment. However, sprites have stayed almost unchanged in the menu section when you look up your Pokemon party. This is the small version of the sprite, and since there is no other way to change the sprite or improve it, the game programmers have decided to keep it for simplicity purposes. Some might be thinking: why have sprites gone from static, better looking sprites, to ones where the pixels can be seen?
That’s a good question, because it is the change from static, 2D battle scenes, to 3D battle scenes where Pokemon move. Even though the animation loops, it’s still pretty nice to watch, and a nice added feature. If the programmers could mix the brief animation when the Pokemon is sent out and the looping animation, I bet the new battle system would be a huge success.
One last note is about shiny sprites. Their sprites have been modified to fit their new color. A red star notes shinies, and there is a brief sparkling sound when they are sent out. Shiny or not, Pokemon sprites have come quite a long way, and should be appreciated.