Configuring Artifactory as a Docker registry mirror using the mirror field in Docker’s daemon.json is not a supported configuration, due to a limitation on Docker's side.
Docker’s mirror feature was designed specifically for DockerHub and does not support mirroring private or external registries like Artifactory. This is confirmed in Docker’s documentation here:
“It's currently not possible to mirror another private registry. Only the central Hub can be mirrored.”
To properly pull images from Artifactory, use the full repository path as shown in the Set Me Up section of your Docker repository in Artifactory:
JFrog_URL/docker-repo/DockerImage:DockerTag