What was the specific nature of the service Mavshibai performed for Sai Baba, and how was it perceived by others?

Mavshibai, whom Baba called "Mother," served him with what is described in Chapter 24 as incomparable devotion. Her method was quite extraordinary; she would press Baba's stomach and sides, twisting with both hands to "grind" and "churn" his stomach like a pot of buttermilk. This vigorous service caused Baba's body to move up and down. While this was an expression of her pure and guileless love, it was perceived differently by Anna, who felt pity in his heart watching the strange service. Despite the jolting movements, Sai Baba himself seemed completely at ease, accepting the excellent service borne of pure love.