As Dan pointed out, by default you need to manually revert dired buffers (e.g., by typing g) in order to update the directory listing view.
If you want this to happen automatically, then you can turn on auto-revert mode. For example,
(add-hook 'dired-mode-hook #'(turn-on-auto-revert-mode))
But see here for some limitations of this.
You might also want to combine that with
(customize-set-value 'auto-revert-verbose nil
"Prevent any auto-revert messages from
obscuring the minibuffer at crucial times!")