What was the most important figurative language in Act 2 of Julius Caesar?

But 'tis a common proof / That lowliness is young ambition's ladder, / Whereto the climber-upward turns his face; / But when he once attains the utmost round, / He then unto the ladder turns his back, / Looks into the clouds, scorning the base degrees / By which he did ascend. (II, i, 21-7)

This is important because almost everyone (Brutus being the exception) falls prey to ambition.