I was wondering if all the sprites within a spritesheet must be of the same size or not for a single animation.

Let us assume that I have a spritesheet for a walking animation and I was trying to slice the spritesheet so I could get each frame of the animation and it happens that one of the animation frames has different size (2 pixel more in width) than the other frames.

So how can I handle this situation should I make all the sprites the same size by slicing a bit from the transparent background so all the sprites can have the same size for the animation or should I just slice all the sprites as much needed so I can have some of the frames with different sizes?

I'm also wondering if the filter mode when using sprites should always be "Point (no filter)" or not.