This simple and splendid blank verse tells me that life is ever changing and ever beautiful. Though we experience sunset and sunrise everyday, we never feel the monotony of this daily routine. Each dawn is fresh and makes us aspire for a new beginning in life too.
Imagery-
Imagery is quite visual with aptly used figures.
"Sunlight breaks through a metalic sky
A serene explosion of daybreak."
I notice the play of adjective phrase in "serene explosion." Two words with opposite meanings are brought to produce a new situation!

Flow-
Flow is smooth and spontaneous because the poet has used iambic pentameter impressively and with discretion throughout the poem.

Write on!