I can't confirm with Mac OS X > 10.9.5.
Does switching for alternate "border-Mode" change anything?
'layout-marks' vertically like the default. No header, no footer
Yes, when changing the 'marks' to horizontal, one can drag those 'marks'
Edit: Typing mistake - vertical has nothing to do with 'default', while writing this posting, I deleted the word 'not' )-:
This does not seem to have anything to do with the iPhone Stencil. I can reproduce on my windows system with layouts of different widths and heights, not just the iPhone stencil.
I'm not surprised by this behavior however. The system thinks that I am hovering the mouse over the object to select it, not to pull a part border down to resize it. If I then drag the rectangle out of the way, I can resize the layout and then drag the object back into position. but a position difference of just one pixel is enough to see different results. I used the down arrow key to nudge the rectangle down until I go the message offering to resize the layout, clicking "no" to make sure that I had moved the object down as far as it would go.
Thank You for Your answer! Yes, I know that is not stencil dependant - I just wanted an example that can be replicated
The problem is that one can not drag the layout-bottom-border _outside_ the active part of the layout (the 'right' arrow in the screenshot)
Correct and this is an irritating aspect of the layout design that makes no sense to me. Hence the need to tweak the rectangle up a few pixels in order to get to a place where you can drag the border down in order to resize the layout part.