Allston moved beyond mere imitation of European masters like Claude Lorrain to create a more atmospheric and psychological style. He often focused on the internal reactions of his subjects to unseen terrors. In his painting of Spalatro, he chose to omit the supernatural bloody hand entirely. He focused instead on the assassin's face to convey guilt and fear. This method required the viewer to use their own imagination to complete the scene. His work often features gnarled trees and dramatic lighting that suggests a world where the boundaries between reality and the supernatural are thin.

Modern collectors find a unique mood in Allston’s work that differs from the more literal depictions of nature common in nineteenth-century art. His prints offer a sense of mystery and quiet tension that suits contemporary interiors. The focus on psychological depth and the atmospheric quality of his coastlines or forests provides a sophisticated alternative to traditional pastoral scenes. These works represent Allston's interest in the dark and the mysterious.