1. You have to tow the company line as a line manager or else you'll be fired.

2. If you are a dead-eyed shill for the company your employees won't trust you and you'll be an ineffective manager.

Calling this work dynamic being two faced puts the wrong tone on the behavior. It's more akin to leading a resistance cell in under an authoritarian regime. When the people above you demand unwavering unquestioning loyalty it's the best you can do.

It becomes two-faced if you actually agree with the higher ups but pretend you don't to your employees. Everyone, including your employees, understands the need to "we love Great Leader, so intelligent and wise" in public and won't judge you for it.