Shopify Remix App - Rendering Theme Extension within main jsx app files

[Thegraske]

Hello,

I was browsing through some apps and found one that renders it's Theme Extension as a "Preview" which also changes based on different settings on the left:

I would like this feature in my app that I am building but not sure how am I supposed to:

1. Import it inside one of jsx files e.g. app._index.jsx

2. Render it 

Does anyone have any suggestions/ideas?