The grace of Christ is the gratuitous gift that God makes to us of his own life, infused by the Holy Spirit into our soul to heal it of sin and to sanctify it. It is the sanctifying or deifying grace received in Baptism. It is in us the source of the work of sanctification: "Therefore if any one is in Christ, he is a new creation; the old has passed away, behold, the new has come. All this is from God, who through Christ reconciled us to himself" (2 Cor. 5:17-18). (Catechism of the Catholic Church, par. 1999)
In each sacrament God is revealed and gives himself to the recipient in a supernatural way. It calls for a free response, and a linking or a bending of our own intellect and will to the Giver of Grace. Behold: It almost always is reflected in a happy face.
For some of us, responding to grace, or witnessing grace at work in other's lives will always produce very powerful emotions. (Emotionalism is never an indicator of grace's efficacy, but emotions don't discount its presence either.)
Grace, while so beyond our emotions in magnitude, also seems personal enough and particular enough that it moves our emotions, plain and simple. Still, in truth, it is bigger and deeper and wider than anything we can describe or rationalize. And it touches us in places that we often fail to know or even admit.
Grace is a mighty gift, an unmerited one. I'm not worthy of it on my own, but I've come to receive it with a grateful heart as I try to make a return on the Lord's investment—for freely I have received, so I must freely give (cf.Mt.10:8).
That's what I see in those happy photographs, besides all the fancy dressing up and the parties, and the joyful smiles. I see the lavishness of God both in and through the gift of himself, and through the giftedness of his grace flowing through the people and church in their midst.
This is still the Eastertide: May we revel in the lavishness of such grace . . . and lovingly respond to it with everything we are.