Frank J. Wilstach, comp. A Dictionary of Similes. 1916.

Unreal

Unreal as a dream.
—Frederick William Faber

Unreal as the shell-heard sea.
—Eugene Lee-Hamilton

Half unreal, like music mingling with a dream.
—John Kenyon

Unreal as a painted city on a stage backdrop swayed by a wandering draft.
—Louis Joseph Vance