VIRGO MATER CHRISTI
VULTUS EUCHARISTICI ADORETRIX
Adoretrix is very much a noun, like “mediatrix” (third declention, nominative singular, feminine, to be precise). Chrck with another Latin scholar first, but I would render the literal translation this way:
Virgin Mother of Christ, adorer of the Eucharistic Face (or "the Face of the Eucharist).
There is no verb in this phrase, which makes sense if it’s on a picture because the implied preface is “This is the …” or “Behold …”
But let me re-stress that you check with a Latin scholar. There may be something idiomatic in the phrasing that is completely lost in a literal translation. I’m somewhat certain that “face of the Eucharist” should be rendered another way in English, a way that only exists in Latin by saying it the way it’s written.