It's actually pretty amazing how the two interactions between the heroine and miss bertia compare to each other. I actually think the chapter is used to highlight how in the otome game ver. prince cecil never actually came to 'love' heroina and it was only his obsession with his toy. But with bertia, he realized how much he loved her and how many different emotions she made him feel, rather than just regarding her as a toy in the end an referring her as such in his mind.