Final answer:
Diana advises Lyddie to move away from the window with poems and plants to protect them from smoke and drafts, ensuring a stable environment for their wellbeing.
Step-by-step explanation:
Diana tells Lyddie to go away from the window with poems and plants likely because the presence near the window may not be beneficial for the plants that need a stable environment free from disturbances such as smoke or cold drafts that could come from the window being opened frequently by Lyddie. Poems and plants both represent delicate items that require care and a peaceful setting to thrive. This scenario symbolizes the need for a nurturing environment for growth, whether it be for living plants or the flourishing of art and poetry.