From [literarydevices.net]

William Shakespeare has used this phrase in his popular play, Richard III, where King Richard is expressing his feelings of discontent regarding living in the world that hates him. He begins his soliloquy by stating, “Now is the winter of our discontent/Made glorious summer by this son of York…” (Act-I, Scene-I). Apparently he seems to be protesting his family’s repression, and his own discontent; however, actually he is celebrating the upturn of fortunes of his family, as his brother becomes the king.

In this case, we get the idea that he is not happy with his current state of affairs. We can say he starts grumbling about his brother becoming king, and broods over his deformity — having been born disfigured, and a hunchbacked.

Sounds right!