diff --git a/wp-includes/class-wp-customize-manager.php b/wp-includes/class-wp-customize-manager.php
index d12eea0e5f..51e979dfe0 100644
--- a/wp-includes/class-wp-customize-manager.php
+++ b/wp-includes/class-wp-customize-manager.php
@@ -5198,10 +5198,9 @@ final class WP_Customize_Manager {
 				array(
 					'label'       => __( 'Site Icon' ),
 					'description' => sprintf(
-						'<p>' . __( 'Site Icons are what you see in browser tabs, bookmark bars, and within the WordPress mobile apps. Upload one here!' ) . '</p>' .
-						/* translators: %s: Site icon size in pixels. */
-						'<p>' . __( 'Site Icons should be square and at least %s pixels.' ) . '</p>',
-						'<strong>512 &times; 512</strong>'
+						/* translators: %s: Site Icon size in pixels. */
+						'<p>' . __( 'Site Icons are what you see in browser tabs, bookmark bars, and within the WordPress mobile apps. They should be square and at least %s pixels.' ) . '</p>',
+						'<code>512 &times; 512</code>'
 					),
 					'section'     => 'title_tagline',
 					'priority'    => 60,
diff --git a/wp-includes/customize/class-wp-customize-site-icon-control.php b/wp-includes/customize/class-wp-customize-site-icon-control.php
index 942000a57d..33694b2a60 100644
--- a/wp-includes/customize/class-wp-customize-site-icon-control.php
+++ b/wp-includes/customize/class-wp-customize-site-icon-control.php
@@ -66,11 +66,47 @@ class WP_Customize_Site_Icon_Control extends WP_Customize_Cropped_Image_Control
 							<img src="<?php echo esc_url( admin_url( 'images/' . ( is_rtl() ? 'browser-rtl.png' : 'browser.png' ) ) ); ?>" class="browser-preview" width="182" alt="" />
 
 							<div class="favicon">
-								<img src="{{ data.attachment.sizes.full ? data.attachment.sizes.full.url : data.attachment.url }}" alt="<?php esc_attr_e( 'Preview as a browser icon' ); ?>" />
+								<img src="{{ data.attachment.sizes.full ? data.attachment.sizes.full.url : data.attachment.url }}" alt="{{
+									data.attachment.alt ?
+										wp.i18n.sprintf(
+											<?php
+											/* translators: %s: The selected image alt text. */
+											echo wp_json_encode( __( 'Browser icon preview: Current image: %s' ) );
+											?>
+											,
+											data.attachment.alt
+										) :
+										wp.i18n.sprintf(
+											<?php
+											/* translators: %s: The selected image filename. */
+											echo wp_json_encode( __( 'Browser icon preview: The current image has no alternative text. The file name is: %s' ) );
+											?>
+											,
+											data.attachment.filename
+										)
+								}}" />
 							</div>
 							<span class="browser-title" aria-hidden="true"><# print( '<?php echo esc_js( get_bloginfo( 'name' ) ); ?>' ) #></span>
 						</div>
-						<img class="app-icon-preview" src="{{ data.attachment.sizes.full ? data.attachment.sizes.full.url : data.attachment.url }}" alt="<?php esc_attr_e( 'Preview as an app icon' ); ?>" />
+						<img class="app-icon-preview" src="{{ data.attachment.sizes.full ? data.attachment.sizes.full.url : data.attachment.url }}" alt="{{
+							data.attachment.alt ?
+								wp.i18n.sprintf(
+									<?php
+									/* translators: %s: The selected image alt text. */
+									echo wp_json_encode( __( 'App icon preview: Current image: %s' ) )
+									?>
+									,
+									data.attachment.alt
+								) :
+								wp.i18n.sprintf(
+									<?php
+									/* translators: %s: The selected image filename. */
+									echo wp_json_encode( __( 'App icon preview: The current image has no alternative text. The file name is: %s' ) );
+									?>
+									,
+									data.attachment.filename
+								)
+						}}"/>
 					</div>
 				<# } #>
 				<div class="actions">
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 4043a32009..2316ed0a25 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.5-beta3-57729';
+$wp_version = '6.5-beta3-57730';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.