You can use your own logo in each document. You can upload pictures in .jpg, .png and .gif format. Open the settings from the context menu in the kiosk or via the detail page.
Click on "Settings".
Next click on the index tab "Appearance". To select an image from your computer either click "select file" or drag an image into the gray marked area. To upload a logo, proceed in the same way as you already know from uploading your PDF file. Then save the settings, and the logo will appear in the preview.
Please keep in mind: the logo is not allowed to be larger than 250 x 100 pixels.