A later post on SN shared the above Tweet as well.

*Coldcard Mk4 - NFC demo*
https://stacker.news/items/16602
https://twitter.com/eh_deee/status/1507820692401709057

cryptocoin

Another demonstration:

> Its time to show off [@Coinkite](https://twitter.com/Coinkite)’s newest [@COLDCARDwallet](https://Twitter.com/COLDCARDwallet), the Mk4 🔥🔥🔥 In this quick video tutorial, I go through the process of extracting a wallet address from the hardware device onto a mobile phone. Take a look! 👀
>
> [Video]

https://twitter.com/eh_deee/status/1507820692401709057

bitcoin

🎥 Demonstration of transferring data from NFC-equipped COLDCARD wallet MK4 to mobile | @econoalchemist

Here's a Tweet by NVK showing the best wireless signal connection between the MK4 and an iPhone. 

> This is the NFC sweet spot for iPhone and Mk4 @COLDCARDwallet
>
> Lean in, between 5 and 8 rows.
>
> (Had to use my dead phone taking a pic with my good phone)
>
> Until wallets integration happen, you can use any NFC tools to get addresses, xpub, etc.
>
> ![NFC best signal with iPhone](https://pbs.twimg.com/media/FOjnVxTX0AMGEBv?format=jpg)
> [Larger image](https://pbs.twimg.com/media/FOjnVxTX0AMGEBv?format=jpg)

https://twitter.com/nvk/status/1506708441045286917