You can select what kind of content you want to use here. You can use an image, text, or even custom HTML or multimedia contents.
You can also find buttons here for different screen sizes. With that you can enable/disable the current layer on the specific devices. Learn more about that feature here: Hide layers on specific devices.
With the button Click to set you can open the Media manager and place a desired image to the slide.
With the text option, you can also easily set heading lines or even just a paragraph.
You can place any custom HTML content into the layer.
YouTube, Vimeo or self-hosted videos with their embed code are also welcome. Under the How Tos section of the documentation you can learn more about them. As you can see there are additional parameters appear in this tab:
You can add a poster image to your video, which will appear when the video is not started yet. You can add an image by Url, or even choose one from your image library.
If you enable the Use this video as slide background the video forced to fill up the whole slide. It is recommended to set a poster image in that case, to make that load immediatelly, while the video is still loading in the background. Please note that if you also have a slide background image, then that will cover the video.
When the background video feature is enabled you can choose built-in effects to appear as an overlay on the video, to make it more spectacular, adn also help to keep the text layers readable. When you don't have the video set as a background, you will see options for that, like Autoplay, Fill mode or Volume. The Controllers and Info can be also switched on/off.
Under this tab, you can place different type of contents into the layer. You can learn more about that feature here: Dynamic slides.