Whimsical Riddles for Your Cherished Creature

In a sphere of feathers, silent and still, what gentle vessel rocks the dawn, upon yonder windowsill?
It dances upon currents unseen, whispering wisdom in evergreens' dreams, what is missed, yet yearned and foreseen?
A mirror of time past, a painter of shadows vast, what roams, 'neath tethered silk, unseen and ever-fast?