Makes an element as tall as possible while remaining within the slide bounds.
Stretch Example
Image byline
Image byline
Stacks multiple elements on top of each other, for use with fragments.
<img class="fragment" width="450" height="300" src="...">
<img class="fragment" width="300" height="450" src="...">
<img class="fragment" width="400" height="400" src="...">
One at a time.