Content items are windows to your content that can be moved around and interacted with onscreen. You can use multi-touch gestures to enlarge/shrink, rotate and reposition them.
When you touch on a content item a toolbar appears briefly (at the bottom left) revealing additional controls. In some cases, depending on the content, a close button will appear at the top right of the item, allowing you to close and hide it from the current presentation.
In most cases you'll see the annotation, fullscreen and favourite (star) buttons on each content item. These can be toggled on/off to activate those functions.
For other types of content, the buttons in the toolbar may appear differently.
Videos
Videos show an overlay seek bar (drag on it to seek to a different playback time in the video), and the toolbar has buttons for play/pause, rewind (to beginning of video), mute, loop, and fullscreen.
Documents (PDFs)
Documents have tool buttons for enabling zoom mode, annotation, favourite and fullscreen.
Web pages
When a web page appears fullscreen on a page, a reduced set of buttons will appear like the example above. This has buttons for web page navigation (backwards and forward), stop/reload and onscreen keyboard.
When a web page is 'floating' on the page (i.e. it can be freely moved around and re-sized) additional buttons will appear like the example below. This has special touch (hand) icon, enabling you to fix the web browser window in-place on the screen to then be able to scroll or interact with the web page, as well as a fullscreen button.
Repositioning the Toolbar
You can touch and drag on the 3 dots (on the left) to reposition the toolbar to another location on the content item. For example, the image below shows the toolbar dragged to the right hand side of the object, to help with presenting the content on a large screen (or to avoid obscuring content).