If you upload tranaparent files to Imageshop, a greyish/white squared pattern will be added behind the motive, so that it appears more clearly. However, this does not apply to transparent files with white motives. The motive and the background will both appear white on the thumbnails that illsutrates the motive inside Imageshop.
To solve this, you can add color to the background. To add color, clickthe detailed versjon of the image (the "i" in bottom right corner), and then click the blue button "Edit thumbnail" under the image. This will open awindow where you can edit the thumbnail, choose background color and save the thumbnail The original file and the downloadable versions will not be affected.
The name in the logo is white, and does not appear.
Click the blue "edit"- button and you will be taken to the step below, where you can add a background color, preview and save the thumbnail: