all my loli wolf companions are so moe
they actually have official sizes for pokeballs and item ballsyour argument makes no sense since they recycle sprite assets in the overworld a lot and half of the pokemon you talk to share one sprite. An actual pokeball is obviously not as big as it shows on the overworld either, since its there as a representation, just like everything else.
anyway, that's the point - 8 bit games like DQ have mimic chests resemble typical chests, but when encountered they are outright mentioned as transforming into monsters. I mean, they could have just said "voltorb can alter its size" and it would have fixed many of its problems