ratio1:
Yeah I know one parish does that too. But I’m wondering is this a special alleluia for Easter or is it just an “ordinary” alleluia among others?
If you need a precise answer, that “Alleluia” is the antiphon for the Solemn Lauds of Easter Day, which was attached to the Easter Vigil after Communion, although with Psalm 150. I’m not sure where your screenshot is from, but that might also be from a version of the Easter Vigil that uses the same Alleluia tone for a simpler First Alleluia of Easter.
Today, you can use that tone throughout the year for the Gospel acclamation at Mass.