The topic of what mages look like could span many, many articles. But suffice it to say that a wizard in Magic doesn't have to be a shriveled white dude with a long beard and a pointy hat. In fact, in Magic, those are far outnumbered by dynamic, powerful mages of all shapes and sizes.
Check out the Tenth Edition art for Arcane Teachings next to its Judgment counterpart. Not only is the old art not a great fit for a red aura of fire and strength, it also doesn't communicate this sense of mages as beings of immense power and dynamic potential. In a game about spells, mages are the ultimate badasses.
Here are some Tenth cards that depict spellcasters in the way that nails the look of Magic's powerful, badass, active mage.