Blog featured images way larger than in demo

Hey, I purchased the theme based on what I saw in your official demo (https://catchthemes.com/demo/kids-camp-main/) The blog section there has *way* smaller (also different format) pictures and also a smaller headline size than the result I have in the real blog now: https://wp-test.ejw-neuenbuerg.de/ (Section: Aktuelles) Why is there such a huge discrepancy and how can I achieve the same look as in the official demo?