In this case, when flashing, booting or testing a board, LAVA will run the tool for deploying, booting or testing from inside a docker container instead of using the host tools. With this feature you can use a custom version of fastboot that is provided as a docker container.

In this case, the device under test is actually a docker container that lava will deploy, boot and test. Just like a board or qemu device-type.

Rgds