Source @Aaronp613 recently said, Apple Watch in the installation of yesterday’s release of the watchOS 10 Beta 5 update, added support for NameDrop function. The feature is an extension of Apple’s existing AirDrop feature that makes it easy to share contact information.

Users simply put two iPhones together, or put an iPhone and an Apple Watch together, and you can send your email account and phone number, as well as your “poster” to the other iPhone.
Apple’s official description of this feature:
NameDrop is a new drop experience that allows users to bring their iPhone close to another iPhone to share contact information with a designated recipient.
Users can also choose which specific contacts they want to share and, importantly, which ones they don't want to share. Users can also share content such as photos or links in the same way.
Apple Watch users can also use the NameDrop feature by tapping the Share button in a card in the Contacts App, or by tapping on a card's complication on the dial and subsequently placing an Apple Watch with someone else's Apple Watch.
As with all drop-sharing experiences, these new features allow content to be shared securely over an encrypted link.