What is the "gleam in the gloom" and how does it turn the tide of the battle?

Exactly when overcome for the powers of good appears to be unavoidable, Bilbo's sharp eye notices the hawks drawing nearer. The sparkle alludes to the last beams of sun and the agony of the losing fight as the falcons swoop down to complete the war unequivocally. This was taken from the book. The Hobbit page 268,

You should provide a picture to show where the arrow is pointing and which information that is given. but there are 3 branches of the government, legislative, executive, and judicial. legislative makes laws, executives pass laws, and judicial are the courts