You must have a main visual element on your campaign. You have the choice between adding a picture or a video. You can change it later at any time.
Regarding pictures, accepted formats are .jpg, .png and .gif. Pictures will be resized to fit a width of 600 pixels on your campaign page while proportion will be maintained. We recommend your original picture’s size to be the closest from this number.
Regarding videos, you must first upload it on one of the following websites: Youtube, Dailymotion or Vimeo. Then, share the link of the video (URL) in the dedicated form and save.