During the performance of The Strawberry Alarm Clock's song "Rainy Day Mushroom Pillow" in the film, the appearance of the lead guitarist's guitar changes halfway through it.
When Jenny, who is deaf, is in Stoney's bedroom for the first time, she reacts to the sound of the cat meowing.
Susan Strasberg plays the deaf Jenny, but not with any trace of speech impairment. She speaks with the perfect articulation and diction of someone raised in a stage and film family, which she was.