How to view a deck's source
To view a deck's source, press the Share button below the deck to open a menu of options. Then press the View deck source option to bring up a list of all the Cards in the deck. Lastly, tap a card to open the Editor for that card.
From here, you can open the Inspector for anything in the card to read it and understand how the author created it. For example, you can read its Rules and logic, or view its artwork and music. You can also make experimental changes to the card and test them by pressing the play button.
If you want to save your own copy of the deck, you may be able to Remix it, unless the author disabled remixing for this deck.