You remind me of the mountain peaks
--- Back marking is described as "Snowy white", and she is grey. So mountain peak because rock and snow.
Though you are anything but cold
--- is probably a warmblood, and also isn't super cold
Your scent is of the earth, the sky forbidden from your kind
---- is an equine/can't fly
But I imagine you dream aloud despite your limitations
-----Does express her emotions, once she warms up to you
In contempt for your warm façade, you hide your true intentions
--- Can be guarded.
I should guard my heart, lest you take it in the night
---- "If you've won her heart or loyalty, it's everlasting. "