I think the idea is that the Arcana check to detect magic that ISN'T OBVIOUS gets harder as the magic gets more powerful.
Anyone can see that a flaming sword is magic. Ditto a flying carpet that's flying. Also, an item may not be obviously magical but has so much bling hanging off it that you want to hang on to it anyway. But if something is magical but not obviously so... then that's when you roll the check.
Anyone can see that a flaming sword is magic. Ditto a flying carpet that's flying. Also, an item may not be obviously magical but has so much bling hanging off it that you want to hang on to it anyway. But if something is magical but not obviously so... then that's when you roll the check.