Aztec Demo app: playable media (audio, video) not being shown

[mzorz]

Expected

On the demo app, audio and video should show an icon and when tapped should bring the player up.

Observed

Instead of that, the shortcodes are displayed in raw text.
Tested and found this is so since 1.3.5: Up to version 1.3.4 we had video and audio working in the demo, but then it got lost (instead of showing the image/icon it shows the shortcode tag). We'll need to check it again and make it work again. Apparently, this might be related #689

It's worth checking whether this is expected or not and either document or fix it.

Reproduced

1. launch the demo app
2. observe the audio and video files are represented in raw shortcodes (no visual representation)

Tested

[Google Pixel] on [8.1], since 1.3.5 and on