Creating app with changing image, pop up question dialogue for each image, etc.

I want to make a multiple choice test that does this:

1. reads a number of files, pictures, sounds, whatever. Plays or displays them for a given amount of time.
2. the media disappears and a question box appears right over that file
3. after recieving user input it is right onto the next media file

I amt trying this with images first, but the image always pops up in a new figure window! I can not get it to work inside the app window.

By APP I mean I am using the matlab new app/ app designer feature. Here;s the code:

classdef apptest_02_17_2020 < matlab.apps.AppBase

    % Properties that correspond to app components
    properties (Access = public)
        UIFigure  matlab.ui.Figure
        Image     matlab.ui.control.Image
    end



    % Callbacks that handle component events
    methods (Access = private)

        % Code that executes after component creation
        function startupFcn(app)
            myFolder = 'STIMULI\FACES_ADULT';%use a relative file path to the matlab main app/script
filePattern = fullfile(myFolder, '*.jpg'); % Change to whatever pattern you need.
theFiles = dir(filePattern)
imageArray=(1:1:length(theFiles))
picturenumber=(1:1:length(theFiles))
for k = 1 : 1 : length(theFiles)
   %im=imread([num2str(k) '.jpg'])
   fprintf(1, 'Now reading %s\n', [num2str(k) '.jpg']);
  % Now do whatever you want with this file name,
  % such as reading it in as an image array with imread()
%pic(k)=imread([num2str(k) '.jpg']);
im=(imread([num2str(k) '.jpg']))


im=matlab.ui.control.Image


matlab.ui.Figure=im
   % Display image. 
   imshow(im);  
 % Force display to update immediately.
  drawnow 
  pause(.1)

end
        end

        % Callback function
        function ImageClicked(app, event)
           
        end
    end

    % Component initialization
    methods (Access = private)

        % Create UIFigure and components
        function createComponents(app)

            % Create UIFigure and hide until all components are created
            app.UIFigure = uifigure('Visible', 'off');
            app.UIFigure.Position = [100 100 640 480];
            app.UIFigure.Name = 'UI Figure';

            % Create Image
            app.Image = uiimage(app.UIFigure);
            app.Image.Position = [256 189 161 153];

            % Show the figure after all components are created
            app.UIFigure.Visible = 'on';
        end
    end

    % App creation and deletion
    methods (Access = public)

        % Construct app
        function app = apptest_02_17_2020

            % Create UIFigure and components
            createComponents(app)

            % Register the app with App Designer
            registerApp(app, app.UIFigure)

            % Execute the startup function
            runStartupFcn(app, @startupFcn)

            if nargout == 0
                clear app
            end
        end

        % Code that executes before app deletion
        function delete(app)

            % Delete UIFigure when app is deleted
            delete(app.UIFigure)
        end
    end
end