as belonging to another earth, the habitations of another race of beings
The simile is telling here. We will discover in the next chapter that the Alps can, indeed, support another "race" of beings. Yet, however much human imagination may discern in these altitudes the possibility of a transcendence of the human condition, neither a human nor another kind of being can effectually manage to do so. Moreover, "another race" of beings, if brought down from an imaginary conception to the solid ground of normative human existence would be considered, like Victor's Creature, alien and hounded from human society. The conflict between the unrestricted imagination and human society is total.