Whatever else the Lady of Shalott has going on, she's definitely alone. We don't know who shut her away in the castle or why, but it doesn't seem fair. We can tell that she's fed up with it; in fact she even says as much. Her desire to be part of the world, to interact, to love and be loved, is what pushes the whole plot of this poem. The fact that she never really breaks out of her loneliness is what gives "The Lady of Shalott" a tragic edge.
The Lady of Shalott makes a confident choice to break free from her isolation. Although it costs her everything, it's still a strong and meaningful refusal of her shadowy, isolated situation.
The Lady of Shalott is engaged in lonely weaving, a traditional mode of women's labor. Her imprisoned isolation is a powerful metaphor for the social, sexual, and intellectual repression of women across English history.