The normal logo upload that is part of the site settings area is hidden for these two skins. The skins page is where the logo should be uploaded. The reason for this is so these skins can use a very large area, the whole header, for a logo and/or advertisement area. The skins page indicates what size in pixels all the images should be uploaded to get the best possible outcome. Uploading a smaller image here will cause issues. We have adjusted the skin so that smaller logos will not repeat, but ideally you will want to customize this area correctly with an image that fits this entire area.