Another painting by the artist Tintoretto shows the Mannerist style. This is the Presentation of the Virgin.
Young Mary climbs solemnly up the stairs to the temple, and although she is the most important figure of the painting, she is small. The artist intended this to produce excitement in the viewer. This is a dramatic moment being depicted, and tons of things are exaggerated, as seen in the elongated figures, dramatic gestures, odd perspective, and strange lighting. It looks realistic enough, but Mannerism exaggerates and deforms (slightly) its figures and subject matter. It was the reaction to the harmonious Classicism and idealized naturalism of High Renaissance art, concerning itself much with solving intricate artistic problems, such as portraying nudes in complex poses, different, heavily-contrasted lighting styles, etc. Renaissance art preferred balance and perfection (like the Greeks); Mannerism took to imbalance and an overly exaggerated (almost to the degree of mockery) version of Renaissance ideals. Surmise from it what you will, and remember that the time of the Reformation was a time of confusion and chaos in the church. Religious paintings are treated differently, as you can clearly see.
This famous statue of the god Mercury by Giambologna shows the Mannerist style of creating difficult poses that were not natural. The figures are graceful but disproportionate.