The Timeline visualizes your slideshow on a time axis.
On top stands the Time Scale with Zoom Controls, On bottom are shown the Slides and Transitions.
A cursor is also displayed and shows the current Viewer time.
There is currently only one kind of slide: the Image slide. In the future, there will also be the content slide (draw texts and shapes) and maybe the video slide.
To add new images to the timeline, simply Drag and Drop them from the Library.
To Select a Slide, simply Click on it.
Selecting a slide will open the related slide Panel: for an image, the Image Panel.
You can change the selected slide by pressing Left and Right arrows.
To remove a slide, select it, then press Delete (or Backspace).
Alternatively, you can Drag a Slide out of the Timeline.
To reorder slides, simply Drag and Drop in the Timeline.
You can also use C-Left and C-Right hotkeys to move a selected slide.
To resize a Selected Slide, drag one of the Orange Arrow:
To add a Transition, simply click on the button.
Exactly like for Slides, you can also select a Transition.
It will open the Transition Panel that allow to customize it.
It also allows to Resize it and Remove it.