Why does the narrator describe Dee's request for the two quilts made in a voice ""sweet as a bird""

In the text, "Everyday Use," we learn that Dee wants to keep the quilts that have been passed down in her family for generations. However, she wants to keep them not because they personally mean something to her, but because she thinks they are interesting cultural items.

One of the characteristics of Dee is that she is quite harsh, and lacks softness or sweetness. However, when she asks for the quilts, she does so in an extremely sweet voice. This fact is included in order to show the reader how false Dee's intentions are, and to reinforce the idea that Dee is asking for the quilts for the wrong reasons.