Index: src/wp-admin/css/site-icon.css
===================================================================
--- src/wp-admin/css/site-icon.css	(revision 33050)
+++ src/wp-admin/css/site-icon.css	(working copy)
@@ -17,6 +17,10 @@
 	max-width: 720px;
 }
 
+.site-icon-crop-wrapper {
+	float: left;
+}
+
 .site-icon-crop-preview-shell {
 	float: right;
 	overflow: hidden;
@@ -56,3 +60,20 @@
 	overflow: hidden;
 	width: 64px;
 } 
+
+@media only screen and (max-width: 768px) {
+	.site-icon-crop-wrapper,
+	.site-icon-crop-preview-shell {
+		float: none;
+	}
+
+	.site-icon-crop-wrapper {
+		max-width: 100%;
+		margin-bottom: 20px;
+	}
+
+	.site-icon-crop-wrapper img {
+		max-width: 100%;
+		height: auto;
+	}
+}
Index: src/wp-admin/includes/class-wp-site-icon.php
===================================================================
--- src/wp-admin/includes/class-wp-site-icon.php	(revision 33050)
+++ src/wp-admin/includes/class-wp-site-icon.php	(working copy)
@@ -267,6 +267,10 @@
 					<p class="hide-if-no-js description"><?php _e('Choose the part of the image you want to use as your site icon.'); ?></p>
 					<p class="hide-if-js description"><strong><?php _e( 'You need Javascript to choose a part of the image.'); ?></strong></p>
 
+					<div class="site-icon-crop-wrapper">
+						<img src="<?php echo esc_url( $url ); ?>" id="crop-image" class="site-icon-crop-image" width="<?php echo esc_attr( $cropped_size[0] ); ?>" height="<?php echo esc_attr( $cropped_size[1] ); ?>" alt="<?php esc_attr_e( 'Image to be cropped' ); ?>"/>
+					</div>
+
 					<div class="site-icon-crop-preview-shell hide-if-no-js">
 						<h3><?php _e( 'Preview' ); ?></h3>
 						<strong><?php _e( 'As your favicon' ); ?></strong>
@@ -284,7 +288,7 @@
 							<img src="<?php echo esc_url( $url ); ?>" id="preview-homeicon" alt="<?php esc_attr_e( 'Preview Home Icon' ); ?>"/>
 						</div>
 					</div>
-					<img src="<?php echo esc_url( $url ); ?>" id="crop-image" class="site-icon-crop-image" width="<?php echo esc_attr( $cropped_size[0] ); ?>" height="<?php echo esc_attr( $cropped_size[1] ); ?>" alt="<?php esc_attr_e( 'Image to be cropped' ); ?>"/>
+					<div class="clear"></div>
 
 					<input type="hidden" id="crop-x" name="crop-x" value="<?php echo esc_attr( $crop_x ); ?>" />
 					<input type="hidden" id="crop-y" name="crop-y" value="<?php echo esc_attr( $crop_y ); ?>" />
Index: src/wp-admin/js/site-icon-crop.js
===================================================================
--- src/wp-admin/js/site-icon-crop.js	(revision 33050)
+++ src/wp-admin/js/site-icon-crop.js	(working copy)
@@ -37,6 +37,7 @@
 		},
 
 		ready: function() {
+			$cropImage = $( '#crop-image' );
 			jcrop_api = $.Jcrop( '#crop-image' );
 			jcrop_api.setOptions({
 				bgColor: 'transparent',
@@ -43,7 +44,8 @@
 				aspectRatio: 1,
 				onSelect: siteIconCrop.updateCoords,
 				onChange: siteIconCrop.updateCoords,
-				minSize: [ wpSiteIconCropData.min_size, wpSiteIconCropData.min_size ]
+				minSize: [ wpSiteIconCropData.min_size, wpSiteIconCropData.min_size ],
+				trueSize: [ $cropImage.attr( 'width' ), $cropImage.attr( 'height' ) ]
 			});
 			jcrop_api.animateTo([wpSiteIconCropData.init_x, wpSiteIconCropData.init_y, wpSiteIconCropData.init_size, wpSiteIconCropData.init_size]);
 		}