Strange duplicate Chrome icon with a display icon within in just popped up

This is a feature called Handoff, which is part of Continuity. It allows you to access apps running on your other devices with the aim of letting you start a task on one device and resume it on another.

On your MacBook Pro, you are seeing a copy of Chrome running on another Mac which is on the same Wi-Fi network, where Bluetooth is enabled on both devices and you are signed in to both devices using the same iCloud account.

It can be turned off by following the instructions in the article linked above.