In "Recuerdo" by Edna St. Vincent Millay) there is a line, "We hailed, "Good morrow, mother!" to a shawl-covered head." What does the "shawl-covered head" refer to?
There wouldn't be one answer, but I could assume that is referring to a person (maybe her mother or a queen) with a shawl covering their head.
When they say "We hailed, 'Good morrow, mother' to a shawl-covered head.", I think it means that they are hailing to their mother or someone dear, who has a shawl covered head. The other option is it could be using figurative language, like a metaphor or idiom. In that case, it could have a different meaning, such as mother could be referring to the earth. In this quote of text, for all I know (I haven't read it), they could be referring to the mother as the queen. Again, these are educated guesses, so there is a good chance I am wrong, but these strategies could help you identify the answer.