I updated the image used after making a new version of my app, I used the command:

kubectl set image deployment/flaskapp flaskapp=username/flaskapp:5 --record

In my first deployment yml file, I used the same name for the deployment, template and containers. Here is the description of the new pod:

  Normal  Pulling    32m   kubelet, ip-192-168-59-27.us-west-2.compute.internal  Pulling image "scientronic92/flaskapp:5"
  Normal  Pulled     32m   kubelet, ip-192-168-59-27.us-west-2.compute.internal  Successfully pulled image "scientronic92/flaskapp:5"
  Normal  Created    32m   kubelet, ip-192-168-59-27.us-west-2.compute.internal  Created container flaskapp
  Normal  Started    32m   kubelet, ip-192-168-59-27.us-west-2.compute.internal  Started container flaskapp

I am using aws loadbalancer, and when I curl the url or using my browser it shows me the same old result.

Note that I tested the new uploaded docker image locally and it worked fine.