In Tuugo you can upload an image or logo that you want to publish. To do this very easily, mouseover on your username, and select "Edit my business" from the dropdown menu
Then, on Business Logo, select an image.
Please keep in mind that image file size limit is 20 MB.
Once you have selected a logo, you can edit the thumbnail shown, by clicking on the image.
Once there, an Editor will display.
Drag with your mouse and select the area you want as a logo, or even you can rotate the image if it wasn't uploaded correctly. You can also customize the thumbnail size, by checking the "customize thumbnail size" and using the squares on the borders of the area to specify exactly what you want to use as a thumbnail.
Once you are finished, click on the "Save" button. If you don't want to save changes, just click on the "Close" button, on the upper right corner.
Please note that in the tab "Photos" of your listing, the original image will appear, but the edited thumbnail will appear as the logo image, and also on the search results, and listing pages.