Adding a logo or image to your e-tickets can be done, however the area in which the logo can be placed is limited. Attached is a copy of a sample e-ticket showing where the logo can be placed (the sections that are highlighted cannot be moved or erased). 

Please note that once you customise your e-ticket's template, it will be applied to all of your events. You can always contact us however and let us know if you would like to change/update/remove the existing template.