No, Share Link does not consume any mobile data when you send/receive files to/from other mobile devices. Share Link only uses a Wi-Fi hotspot, which connects two devices for file sharing.
When sending files, Share Link automatically enables the Wi-Fi to create a hotspot for the receiving devices.
When receiving files, the device must have its Share Link app launched. When the receiver taps Receive files > From mobile, the icons 
and 
appear on the notification bar, which means that the device is tethered to a Wi-Fi hotspot of the sending device and the file transfer will automatically take place.
Note: If you’re the receiver and your device is currently connected to a Wi-Fi network, Share Link will temporarily disable the connection to tether to the sender’s device. Share Link will restore the connection to the Wi-Fi network once the tethering is disabled.
