The most striking feature of Wat Lai is the "large-scale Stucco Reliefs" decorating the exterior walls of the nine-bay Vihara, both at the front and the back. This artwork consists of high-relief sculptures portraying various important scenes from the Ten Great Incarnations and the Life of the Buddha with incredible detail. The uniqueness of these reliefs lies in their complex yet balanced composition, showcasing the superior craftsmanship of the early Ayutthaya period. The artists managed to convey emotions and narratives through the fluid lines of the stucco, from the intricate costumes of the figures to the mythical creatures of the Himmapan forest and various flora. These works have been well-preserved and are considered some of the most complete and perfect examples for the study of Thai stucco art.