Question

In a Facebook canvas app, I’ll like to show some static header and banners fast, when the facebook-sdk is connecting to authorize the app/user.

Answer 1

If you think connecting to Facebook API and fetching the information is taking time, then use output control functions.

The Output Control functions allow you to control when output is sent
from the script. This can be useful in several different situations,
especially if you need to send headers to the browser after your
script has began outputting data. The Output Control functions do not
affect headers sent using header() or setcookie(), only functions such
as echo() and data between blocks of PHP code.

OR

If you want to show some information before you ask user to authroise the app, you can simply don’t ask the user for authorization on load. Based on some user action, you can ask for auhroization.