Currently it is seeking this image at this location:
/ZenCart/includes/templates/template_default/images/logo.png

Make sure that the image is placed at this location:
/ZenCart/includes/templates/lavender/images/logo.png

Also, double check that spelling and the case match where you have edited the file and it matches the actual file as:
logo.png is not the same as logo.PNG or Logo.png