WDTPRS has been sustaining for years now that "active participation" really means "active receptivity". For the most part clerics and liturgists misunderstand this term. I have argued this from documents and from semantic/philological grounds.
Today during the Holy Father’s sermon during the so-called "Mass of the Rings" celebrated on 25 March, the Solemnity of the Annunciation he said this (official trans. with me additions):
From generation to generation, the wonder evoked by this ineffable mystery never ceases. Saint Augustine imagines a dialogue between himself and the Angel of the Annunciation, in which he asks: "Tell me, O Angel, why did this happen in Mary?" The answer, says the Messenger, is contained in the very words of the greeting: "Hail, full of grace" (cf. Sermo 291:6). In fact, the Angel, "appearing to her", does not call her by her earthly name, Mary, but by her divine name, as she has always been seen and characterized by God: "Full of grace – gratia plena", which in the original Greek is kekaritomene, "beloved" (cf. Lk 1:28). Origen observes that no such title had ever been given to a human being, and that it is unparalleled in all of Sacred Scripture (cf. In Lucam 6:7). It is a title expressed in passive form (in forma passiva), but this "passivity" of Mary, who has always been and is for ever "loved" by the Lord, implies her free consent, her personal and original response: in being loved, Mary is fully active (Maria è pienamente attiva), because she accepts with personal generosity (accoglie con personale disponibilità) the wave of God’s love poured out upon her.
The Pope underscores the interior receptivity of Mary. We logically know from this that the active receptivity of Mary is the perfect model of liturgical participation.