It’s maybe a blessing for a woman “binding up her head” for the first time — ie, formally wearing an adult woman’s headgear.
Whatever the blessing is about, what’s interesting is that it includes tons on the theology and Biblical interpretation of women wearing headgear.
Namely, by referring to all Christian women as ideally “fully armed” (kathoplismenai) “in the Faith,” the prayer pictures headgear/veils as helmets, as well as quoting the bit about Christian women adorning themselves with good works, and living with modesty and sobriety.
Early Western scholars associated the prayer with bridal veiling, but apparently this is not it. Nor is it about the veiling of nuns. Now scholars aren’t sure what it’s about, which is something this article tackles.
The blessing refers to “the one who binds her [head] up,” who is referred to as a female person. So maybe this was the woman’s godmother or another sponsor, or her mother, or another female relative or friend. Obviously the prayer instructions do not think this needs to be explained or decreed, so who knows?
UPDATE: How I forgot to link the article, I don’t know. So I’ll link it twice this time.
“The Veiling of Women in Byzantium: Liturgy, Hair, and Identity in a Medieval Rite of Passage” by Gabriel Radle. This scholar seems to have several papers about liturgy, prayers, Eastern marriage traditions of Christians, etc., which are linked in the right hand margin.