Answer:
As she is weaving her magic web, the Lady of Shalott sees Sir Lancelot riding by outside, and she is so taken by his appearance that she stops weaving and looks directly out of her window towards Camelot, bringing about a curse. The world of the Lady of Shalott differs from that of Camelot because she is isolated in a tower, weaving a web, while Camelot is a bustling, active place where knights ride by. The line that describes this difference is "And down the river's dim expanse, Like some bold seer in a trance, Seeing all his own mischance—With a glassy countenance, Did she look to Camelot."