How does the poem, the Lady of Shalott, setting relate to the theme of loneliness?

Shalott is an island, and the Lady is isolated within a tower.

Tremble in the water chilly
Round about Shalott.

And the silent isle imbowers
The Lady of Shalott.

The little isle is all inrail'd
With a rose-fence, and overtrail'd
With roses: by the marge unhail'd
The shallop flitteth silken sail'd,
Skimming down to Camelot.