The idea of aggressive Mycenaeans is definitely seen in their art. Art we see in the Ancient Aegean Wing shows this especially well, in their obsession with predator animals (lions) seen in The Lion Gate entering the citadel of Mycenae. Not only that, but displayed on The Mycenaean Ceramics: the Warrior Krater, there are many people dressed and equipped for war (shields, spears, and armor).
The peace of the Minoans is not as obvious as the aggressiveness as the Mycenaeans, but it is still displayed in their works. The marine style ceramic, the Octopus Flask, is a very good example of this. An octopus isn’t necessarily a commonly seen aggressive animal (like the lion), but the depiction of the cartoon-like eyes makes it more peaceful and playful at first glance. To some extent, their peaceful nature is also displayed in the Kamares Ware Jug, which is decorated with plants and curved shapes, as apposed to square shapes and war figures.