Bestseller Pictures are too big in desktop version

[Maltauschen21]

Hello! 
I just wanted to add a bestseller category to be homepage but it appears to be extremely big and each picture is below the other instead of all in one line. It seems to be correct in the mobile version

Here is the link to the website: www.salufarmashop.com 

EDIT: Actually the pictures on the mobile version are also too big 

How can I fix this? 

Thank you : )