Hopkins' curtal sonnet "Pied Beauty" (written 1877,published 1918) is an unabashed celebration of the wide variety of contrasts found in God's creation the Natural Universe. The Eternal God the Father is the creator and the cause of all contrasting differences in the natural universe.
Man in his foolishness constantly attempts to reshape Nature according to his rules of symmetry and uniformity. He is convinced that God's creation is imperfect and he goes about organising and streamlining and make everything smooth and even. He swears by the mantra of 'sameness.' This results in drabness and monotony. Man's thoughtlessness distorts and perverts God's perfect plan for the Natural Universe.
The poem counters this negative tendency of man by revealing to us the wide variety of contrasts which add colour and beauty to God's creation the Natural Universe. Everything in the Natural Universe -whether on land, air or water- has been created by God to be different and dissimilar.
The central idea of "Pied Beauty" is that variety and contrast are the defining characteristics of Eternal God our Father and Creator. Man instead of complaining and wasting all his time and energy and resources in making everything same and uniform must learn to appreciate this important characteristic of God and praise him always.