The first thing to establish about the Latter-day Saint blessing of a child is what it is not. It is not a baptism, not a christening, and not understood to do anything to the child's standing before God, because Latter-day Saint teaching holds that a child needs nothing done to it. The Book of Mormon condemns infant baptism in unusually direct language, calling it a denial of the mercy of Christ, and the movement holds that children are innocent until the age of eight, which it treats as the age of accountability and at which baptism is administered.
What the ordinance does is name the child and bless it. A few months after birth the family brings the baby to a fast and testimony meeting, and a circle of men holding the Melchizedek priesthood, ordinarily the father with grandfathers, uncles, brothers and close friends, stand at the front and hold the child between their hands. One of them, usually the father, pronounces the blessing.
The child is entered on the church membership record from that point, as a member of record rather than a baptised member, and the name given in the blessing is the name recorded. That administrative detail is the only fixed outcome of the whole thing.