In some cases Replicated pushes application images to a local registry before starting your app. For the native scheduler the local registry is used for both airgap and multi-node scenarios. When the replicated-operator container schedules these re-tagged images, docker will pull it from the local registry, which is a service available on port 9874 of the replicated container.
With the Swarm scheduler the local registry is always used and with the Kubernetes scheduler the local registry is used for airgap installs.