This looks great, I haven't had a chance to install it yet.
But from the screenshots you have a popup window to select the files.

Can I make a suggestion that the file picker is put into a dialog slideout on the right hand side so it fits more into the UI of Umbraco.

Here is a code snippet that I am using on my Umbraco NuGet POC

//Click Button - Pick Files
        $scope.pickFiles = function (folder) {

            //Open a dialog - passing in a ton of options
            dialogService.open({ template: '../App_Plugins/NuGet/BackOffice/Packages/partials/dialogs/file-picker.html', callback: filesPicked, dialogData: { Folder: folder } });


            //When the node has been picked - do this...
            function filesPicked(pickedFiles) {

                //Log the JSON object we get back from the dialog picker
                console.log(pickedFiles);

            }
        };