Kuula supports not only 360x180 photos, but also partial panoramas - i.e. images that do not extend all around. Partial panoramas can be captured with some spherical cameras or with mobile phones. They are also pretty typical in drone photography where the top of the photo (the sky) is often missing.
Unlike Facebook, which requires special meta data embedded in your photo, Kuula assumes every photos is a spherical one when you upload it. In fact, it assumes your photos is a full 360x180 panoramas by defaul. However, in case of partial panos, Kuula expets you to provicde the meta data that indicated the horizontal and vertical angle of your photo.