'Siddhi' has a general as well as a technical meaning. Generally, it is taken to mean accomplishment, success, perfection and prosperity. Baba is Siddhiroopa, that is to say an embodiment of all these. What He wills has to come to pass; what He utters, has to take effect, without delay or diminution. Baba has come to lead man back into the ways of God and so He always wills for the good of man; His utterances are all purifying and beneficial.
Siddhi also means, the superhuman faculties won through Yogic exercises. But Baba had them, even as a child! He invokes them and uses them as His very nature, for the good of man. He says that they are the natural equipment of Divinity, and should not be confused with the skills and tricks that are acquired by Yogis after undergoing certain exercises.
Some ignorant persons are conceited enough to suggest that the use of such 'siddhis' will hinder the 'Spiritual development' of Baba, as if they are Siddhis acquired by Him, as if He (who is the very embodiment of all accomplishments) is a Sadhaka, an aspirant or a practitioner! Baba is the goal of Sadhakas and the personification of all siddhis. He has come to cure those who are afflicted with pride that they possess siddhis and those whose heads are so swollen that they venture to judge the Divine itself.