Why does Chapter 11 emphasize the need to worship a Guru in a physical form?

Chapter 11 explains that for a worshipper who has a physical form or body, the Guru must also be in a physical, or 'Saguna', form for devotion to flourish. The text states that without meditating on this manifest form, loving devotion does not occur, and the 'bud of the mind does not open.' It clarifies that this doesn't mean the formless is separate; using the analogy of ghee being the same substance whether frozen or melted, Chapter 11 teaches that the manifest ('Sakara') and unmanifest ('Nirakara') are one and the same, pervading the universe. This approach is presented as the determination of the scriptures for a devotee with a body.