What the Expand on Click Feature does is growing a embedded video before playing it when the visitor click on it.
For the feature to work the embedded video must be smaller then content area of your theme. Meaning there will be no effect when its already occupying the full width of your content area. This is also the ARVE default, but there is a Maximal Width Setting and the maxwidth shortcode attribute you can set to change that behavior. Aligned videos are by default limited to a maximal width of 400 pixels. The Align Maximal Width setting controls that.
The following examples are with the default setting of ARVE and ARVE Pro
So for a embed like this you would not see the Grow on Click with default settings.
[arve url="https://youtu.be/6pxRHBw-k8M" mode="lazyload" /]
10 Incredible 4K (Ultra HD) Videos
You can either use align, set up a maximal width in the settings or set up a the maximal width individually on videos.
[arve url="https://youtu.de/6pxRHBw-k8M" mode="lazyload" align="left" /] Use align with default settings for this.10 Incredible 4K (Ultra HD) Videos
Use align with default settings for this.
[arve url="https://youtu.be/6pxRHBw-k8M" mode="lazyload" maxwidth="500" /] Set individual ...10 Incredible 4K (Ultra HD) Videos
Set individual videos up for a specific maximal width. Note the the text will always be below the video when no alignment is used.