The word "笑容可掬" is formed by combining the compound "笑容" (smiling appearance) with the phrase "可掬" (can be cupped). "笑" means smile, "容" means appearance, together referring to a smile. "可" indicates possibility, and "掬" means to cup with both hands, so "可掬" conveys something tangible enough to be held. The idiom thus literally constructs the image of a smile so vivid it seems physically graspable.