Ticket #21483: media-controls-test.php

<?php
/*
 * Plugin Name: Customize Media Controls Test
 */

function nhcx_test_customize_media_register( $wp_customize ) {
        $wp_customize->add_section( 'media', array( 'title' => 'Media Controls', 'priority' => 0, ) );
        $wp_customize->add_setting( 'upload_control', array() );
        $wp_customize->add_control( new WP_Customize_Upload_Control( $wp_customize, 'upload_control', array(
                'label' => 'Upload Control',
                'section' => 'media',
                'priority' => 1,
        ) ) );
        $wp_customize->add_setting( 'image_control', array() );
        $wp_customize->add_control( new WP_Customize_Image_Control( $wp_customize, 'image_control', array(
                'label' => 'Image Control',
                'section' => 'media',
                'priority' => 2,
        ) ) );
}
add_action( 'customize_register', 'nhcx_test_customize_media_register' );

add_action( 'wp_footer', 'nhcx_test_customize_media_output' );
function nhcx_test_customize_media_output() {
        if ( is_customize_preview() ) {
                echo '<img src="' . get_theme_mod( 'upload_control', '' ) . '" style="width: 500px;position: fixed; top: 0; left: 0; z-index: 999;">';
                echo '<img src="' . get_theme_mod( 'image_control', '' ) . '" style="width: 500px;position: fixed; top: 0; left: 500px; z-index: 999;">';
        }
}