Spring's flowers and songs—all beauty—could not move the speaker in the beloved's absence; they were mere pale reflections of the beloved.
Sonnet 98 achieves a final inversion: the beloved is the original, and all natural beauty is merely shadow or reflection. Lilies, roses, birds, flowers—all are 'drawn after you, you pattern of all those.' Beauty in nature isn't real; it's a pale imitation of the beloved. The speaker didn't wonder at flowers or praise roses not because he was depressed but because they were recognized as inferior copies. The beloved transcends and contains all natural beauty; everything else is diminished by the comparison.
By making the beloved the archetype of all beauty, the sonnet establishes a metaphysical hierarchy: the beloved is form, everything else is shadow. This elevates the beloved beyond nature into a realm of pure ideal. Yet it also means that any beauty in the world becomes a painful reminder of the absent beloved. The speaker 'plays' with these shadows like a child, but they're meaningless substitutes. Real beauty is gone; everything remaining is a pale echo of what's missing.
Walking through a beautiful botanical garden or seeing Instagram photos of spring breaks in paradise—none of it touches you. You realize everything beautiful is just reminding you of the one beautiful thing you don't have. All these amazing experiences feel like knockoffs.