Hey Jan,
same problem here. Scroll down: http://edtechleipzig.de/
It’s the 2017 WP-Theme, “Footer 2” and what you see is the “horizontal” arrangement: Logos are getting stretched.
Furthermore you see those grey lines behind the logos. They do appear in a different manner also, when displayed vertically.
If you need more infos, let me know!
Many thanks in advance!
Thomas