When there is a comparison between two far-fetched objects that is called-

♦  Conceit: 
- এ ক্ষেত্রে দুটি ভিন্ন রকম জিনিসের মাঝে তুলনা করা হয়।
- It surprises its readers with its ingenious discovery and delights them with its intellectual quality.
- A famous example is Donne's comparison between two lovers' soul and the two arms of a pair of compasses in 'A Valediction Forbidding Morning':

If they be two, they are two so
As stiff twin compasses are two;
Thy soul, the fixed foot, makes no show
To move, but doth, if th' other do.

Source: An ABC of English Literature by Dr M Mofizar Rahman.