Here's why:
* Personification is giving human qualities or characteristics to inanimate objects or abstract concepts.
* In this sentence, "the east of earth" is being personified as something that can be "seen." The east is a direction, not a physical entity that can be visually observed.
The sentence implies that the sunrise or the dawn was easily visible, but it uses the personification of "the east of earth" to create a more poetic and evocative image.