There are two ways that you can create a scene. First tap on the name of a room to open the lights/scene settings. 

To create a picture scene select the scenes dashboard at the top of the page, then select the "+" symbol > Picture scene. You can then select from one of the provided Philips photos or choose to upload a photo from your own camera roll.  Follow the onscreen instructions to save the scene.

To create a scene from your current light settings tap on the lights dashboard. Customize your room lights to your desired settings , then tap on the Scene dashboard and select the “+” symbol > Current light settings. Follow the onscreen instructions to save the scene. Once you have saved the scene it will automatically appear as an icon in the scenes dashboard.

Note: a least one light has to be switched on to create a scene.