Gore simply means that there is blood or gutting (bloody violence explicit in general).

Inside the giantess fetishism


Mortadelo crushed by Mazinger Z: Here we did not resort to explicit violence, as the character enjoys an illogical invulnerability.

The enormous size of the gigas makes it easy for them to destroy, and therefore, to hurt the little ones. The damage that the gigantes do to the smaller ones can be by several forms: crushing (including buttcrush, footprints), bites or chewed, etc.

However, not all the art of gigantas includes bloody scenes. Sometimes artists omit the laws of logic or make the little ones have a certain "invulnerability" (or "elasticity"). So if you are crushed, your body will be unharmed, with a non-mortal pain or simply flattened.