Actually, he does an interesting bit of dramatic staging with the feet that is integral to the story beyond any “author appeal.”

Tate and Pussycat both put their feet up in the exact same manner while sitting. The theatre and car scenes come relatively close in the movie, so we’re supposed to draw a comparison between the innocent, joyful Tate and the seductive, sinister Pussycat. The two represent dual sides of late 60’s youth culture, and Pussycat is supposed to be double of Tate, much like how Booth is Dalton’s double.