How do I remove the white line between my images on squarespace please?

Site URL: https://selwyng.squarespace.com/config/

How do I remove the white line between my images on squarespace, I've tried everything but nothing seems to be working. 

It's the white line right between the website and the dog bowl.

The issue appears to be that the background image does not have a hard edge. There seems to be some kind of edge transition at the top. Images with edge transitions will not blend nicely.

You can either trim the image a pixel or two from the top or you could fill in those pixels with a correct color.

You can see from the pic (view at full size) that is not a clean edge on the top of the image.