Man, that's terrible. How the hell are you supposed to syntax check that, or version control it, or collaborate on it? Extract it from yaml, do a thing, test it, then put it back in yaml, then run it and test it again? And if anyone else wants to make a change to your change, they now have to do the same? What a pain in the ass.

If this is all Docker containers anyway, why aren't they just creating Docker images and referencing them? They're just shoving a Dockerfile into YAML, without the benefit of it actually being a Dockerfile.