diff --git a/packages/block-library/src/image/image.js b/packages/block-library/src/image/image.js
index 090ae83fe50ab9..7bc7fc0594aa82 100644
--- a/packages/block-library/src/image/image.js
+++ b/packages/block-library/src/image/image.js
@@ -434,6 +434,9 @@ export default function Image( {
 						isResizable={ isResizable }
 						imageWidth={ naturalWidth }
 						imageHeight={ naturalHeight }
+						imageSizeHelp={ __(
+							'Select the size of the source image.'
+						) }
 					/>
 				</PanelBody>
 			</InspectorControls>
diff --git a/packages/block-library/src/media-text/edit.js b/packages/block-library/src/media-text/edit.js
index 9df9d0c7a90c97..8472de229f7acd 100644
--- a/packages/block-library/src/media-text/edit.js
+++ b/packages/block-library/src/media-text/edit.js
@@ -291,7 +291,9 @@ function MediaTextEdit( { attributes, isSelected, setAttributes, clientId } ) {
 					slug={ mediaSizeSlug }
 					imageSizeOptions={ imageSizeOptions }
 					isResizable={ false }
-					imageSizeHelp={ __( 'Select which image size to load.' ) }
+					imageSizeHelp={ __(
+						'Select the size of the source image.'
+					) }
 				/>
 			) }
 			{ mediaUrl && (