There comes a time in everyone's life that they must break away from their family and push through life on their own standards. With only the simple dedication of this poem; "To My Daughter, 1954" one can only derive that Yvor Winters had a very close relationship with his daughter and it pained him deeply to let her go out on her own into the real world.
In the first stanza; "This is the terminal: the light" one might believe the terminal refers to a place where all travel begins and ends. In the case of this poem, I believe that it stands for a decision. "The light" refers to the positive aspect of the decision. The terminal "Gives perfect vision, false and hard." This refers to the decisions that she is about to make in her life, some will be difficult and some will not turn out the way she expects.
But in the end, it will be for the best. "The metal glitters, deep and bright" may refer to all the temptations and different avenues she will encounter throughout her journey. The word "deep" refers to those that are more than what they seem and "bright" referring to the ones that shine on the surface but go no where in the end. At the end of the first stanza, in the lines "Great planes are waiting in the yard - They are already in the night" the planes stand for all the different decisions and ways the girl could go out in the real world. Being already in the night means that some opportunities have already been missed.
The second stanza seems to be all about the girl's disposition to going out into the real world. The father describes her as "small" and "Contained and Fragile, and intent".