It means to see the big picture regardless of the minor details.

To see the over-riding view of the system, process, organization, etc. at a senior level.

Examples:  

This class is tough but I remind myself of the 20,000 foot view of getting a degree at the end!

The new CEO looked at the 20,000 foot view of the customer support process and its impact on the company and decided to bring it in-house."