While loitering here on the WordPress Support Forum, trying to answer a topic on resizing the headers “the penny dropped”.
The twentyeleven_setup() function in the parent theme is pluggable, so we can now do so many changes in a single function.
I released a photo blogging theme yesterday and had coded to over-ride the parents functions, like removing headers, new images sizes, new menu's etc:
I stripped out most of what I had done and copied the
twentyeleven_setup() function to my child theme, there I could change lots of the things I wanted to over-ride!
Pluggable functions are functions that can be duplicated without a Fatal Error!
They can exist in both the Parent and Child Theme, if the child themes function is loaded then the parents function of the same name will not be loaded.
I have created a video (about six minutes) and written a short post, you can see more here!