VW Gardening logo not defined

Hi, I purchased gardening theme. All works fine but the logo. Why is not showing in a good definition? I tried to upload it in many measures but no way to get it right. It’s like faded. I exported well in png as the many I usually do. Then there’s a “size logo” option before check it, that only smash it or strech it but not resized well.

Any idea? Thanks.

Mark.