I stumbled upon what might be a bug, or I am just overseeing some features...
When you run this code, the two saved PDFs should be the same because they only differ in their "visible" value. But if the figure's visibility is 'off', the saved PDF is distorted: The white space at the bottom is missing, and the content is streched to the bottom end.
Is this a bug?
clear all; close all;
f1 = figure('Visible','on');
f2 = figure('Visible','off');
edit: what is odd is, that this behavior is only seen when 'ContentType' is 'image'. Saving 'vector' graphics everything is ok.