Yes, my idea behind it is generally draw a sprite, copy it into a new frame, move some parts of it, then reconnect and clean up the ugliness that results from an arm being completely disconnected from a shift in the rest of the image.

According to a pixel artist friend of mine, all the companies he's worked for using those types of anims will build a proprietary tool that essentially works like Flash in a pure-bitmap context; tweening, scaling, rotation, and bitmap cutouts(e.g. parts that bulge and bounce, like the belly of a fat character, simply reuse an area of the sprite and layer it on top). These tools are used for menu layouts and level design as well as sprites.

The figure I've seen is that typically 70% of a game's budget will go to art

wonder what's the typical split between programmers,visual and audio artists in a Zynga game budget