Do you have any other types of trim on the main house that might make sense to put on the guest house too? Shutters for example?

Maybe a pergola over that sliding door could add some depth and interest there?

Thanks Emily - pergola over the sliding door is a great idea. The main house has plantation shutters so that could be a cool tie-in but not sure how it would reduce the height weirdness... Maybe split the shutters horizontally 40/60 with the smaller section at the top (if that makes any sense..)?

I'm thinking to replace sliding doors with French doors, darken paint to "ground" the building and beef up the exterior lights. Wondering if the palms are actually emphasizing the height. I'm thinking tree or climbing roses about equal to the door height.