In DeploymentConfig the selector and labels values are changed when an image is changed from console and this happens only for the key "app: <value>"
If there is no key app added then it by-default adds that key when an image is changed from GUI.

4.11.13

Always

1. Create a DC with selector and labels as given below
spec:
  replicas: 1
  selector:
    app: apigateway
    deploymentconfig: qa-apigateway
    environment: qa
  strategy:
    activeDeadlineSeconds: 21600
    resources: {}
    rollingParams:
      intervalSeconds: 1
      maxSurge: 25%
      maxUnavailable: 25%
      timeoutSeconds: 600
      updatePeriodSeconds: 1
    type: Rolling
  template:
    metadata:
      labels:
        app: apigateway
        deploymentconfig: qa-apigateway
        environment: qa

2. Once the pods are running, edit the DC from CLI and modify the image to other version and save it. The new pod is deployed but there are no modifications in "app: apigateway" under selector and labels

3. Now go to GUI--> Workloads--> DeploymentConfig --> Actions--> Edit DeploymentConfig, in Form view, change the Image Name, Save it and view the selector and labels for "app: apigateway", it is changed to some other value.

The values should not change