Based on the section of the poem "The Lady of Shalott," one detail that is conveyed in the text but not in the painting is:
that the Lady of Shalott is looking toward Camelot.
This detail shows her awareness and longing for Camelot, which is central to her tragic fate in the poem. The painting may depict her in a boat but may not explicitly convey her gaze or her feelings about Camelot.