For me, terror is physical and present (e.g. being pursued by a gore-drenched murderer) and horror is mostly mental - rats in the walls, yellow wallpaper, Conrad, etc. Horror would also describe the reaction to stumbling upon a corpse. Basically, terror involves something coming to get you; horror is about your brain getting itself.
Re: the pics, I'd subtitle them "bad fart" and "where's my bacon".
Terror and horror, from Darwin's The Expression of the Emotions in Man and Animals.
Ann Radcliffe wrote: "Terror and horror are so far opposite, that the first expands the soul, and awakens the faculties to a high degree of life; the other contracts, freezes, and nearly annihilates them."
Or, in Devendra Varma's words, "The difference between Terror and Horror is the difference … between the smell of death and stumbling against a corpse."