The score says how it ended. xG says how it should have ended: it is the sum of the chances each shot was worth, not an opinion about the game.
A draw, but Monza created more (2.10 xG against 0.62) — points dropped.
Parma: +0.6 for the season (15 in the table). Monza: −4.7 (16). The gap between points and xPTS is built from matches like this one.