Can you explain the mystery of Sai Baba's sleeping plank as described in Chapter 10?

Chapter 10 of the Shri Sai Satcharitra details the perplexing way Sai Baba slept. He would rest on a very narrow wooden plank, only about four cubits long and one span (approximately 9 inches) wide, which was suspended from the rafters with old rags like a swing. The chapter notes that his movements were imperceptible; no one ever saw when he climbed onto or descended from this precarious perch. The text explains this seemingly impossible feat by stating that Great Siddhis (powers) resided within Him, making the plank's support merely nominal. It suggests his power of 'Anima', the ability to become minute, allowed for such easy and unseen movements.