I wonder if this has to do with the fact that the EOS 6D typically uses the control wheel to adjust magnification instead of multiple presses on the magnification button. You may be able to get it to behave differently by changing the magnification settings shown on page 245 below:
Thank you for the thought. Your example relates to magnifying a captured image.
I'm referring to the zoom when using live view.
On the 6D there is a 1x 5x and 10x magnification (typically used to check for focus)
When connected to the iPad the screen show when you press the 1x and the 5x.....but the 10 time you see on the LCD camera display, but not the iPad.