Lab 9.1 - Label problems

Hi everyone,

I might have spot a small error, or there is something I missed (sorry if it's the case!)

To question 9 in lab 9.1Deploy A New Service, "If you look back the Pods were given a label of app=nginx"
But I from the .yaml file we have [line 19-22] :

template:
metadata:
labels:
system: secondary

And then the command we're ask to run is :
kubectl get pods -l system=secondary --all-namespaces

To me the command to retrieve the labeled pods is :
kubectl get pods -l app=secondary --all-namespaces

Thanks a lot for the lessons and the numerous discussions available