Spawning a "new window" showing attachement

I’ve got a form that web visitors can submit photos using a file upload control.

Now I am trying to put the approval application in place and I am wondering if

there is a command to open a new “mini-window” with a @Command([AttachmentView])

so that they can see the photo without while still keeping the original form in view.

Is this possible? Is there something along the lines of @Command([OpenWindow) that would

allow me to open the attachment for view in a “mini-window”?