Hi, @Titto84 ,
This is Evita from On The Map.
Can you add your store URL?
The Brooklyn theme has specific logo dimensions that you will want to use in order to prevent your header from bleeding too far into your header image. 450 x 200px (2.25 : 1 ratio) is the recommended logo size.
If you need a free tool to resize your images, you can use LunaPic.
Let me know if that helps!