The abstract is ignoring formating such as center, linebreak and so on. –> Make the abstract format display.
This is apperantly a wordpress by design. I solved it writing the formated code in the abstract field. Then the text is displayed with formating on the tiles.
The link for the messed up images is here: http://web28.milhouse.kundenserver42.de/ChildTheme/ Firefox is ok but IE 11 I get this behaviour.