Here's why:
* "Vemos" means "we see" in the present tense.
* "Manana" means "tomorrow".
* "Mi" means "my".
The phrase doesn't make logical sense in this order. It's missing a verb and a subject.
Possible interpretations:
* "Nos vemos mañana": This means "see you tomorrow" and is a common way to say goodbye.
* "Te veo mañana": This means "I'll see you tomorrow".
* "Vemos mañana mi amigo/a": This means "We'll see each other tomorrow, my friend".
To help you understand the meaning, please provide more context. What is the sentence trying to say?