Modern descriptive idiom (not in xinhua-chengyu.json — flagged in CC-CEDICT only) used for objects, not abstract things.
硕 (shuò, large, ripe) appears in
硕士 (master's degree) but here keeps its 'big and full' sense. Compare
庞然大物 (pángrán dàwù, huge thing) which works the same way but feels more literary.
