diff --git a/src/webp/encode.h b/src/webp/encode.h
index d635fcf0..628b8887 100644
--- a/src/webp/encode.h
+++ b/src/webp/encode.h
@@ -360,8 +360,9 @@ WEBP_EXTERN(int) WebPPictureAlloc(WebPPicture* picture);
 // preserved.
 WEBP_EXTERN(void) WebPPictureFree(WebPPicture* picture);
 
-// Copy the pixels of *src into *dst, using WebPPictureAlloc. Upon return,
-// *dst will fully own the copied pixels (this is not a view).
+// Copy the pixels of *src into *dst, using WebPPictureAlloc. Upon return, *dst
+// will fully own the copied pixels (this is not a view). The 'dst' picture need
+// not be initialized as its content is overwritten.
 // Returns false in case of memory allocation error.
 WEBP_EXTERN(int) WebPPictureCopy(const WebPPicture* src, WebPPicture* dst);
 
@@ -392,7 +393,9 @@ WEBP_EXTERN(int) WebPPictureCrop(WebPPicture* picture,
 // the top and left coordinates will be snapped to even values.
 // Picture 'src' must out-live 'dst' picture. Self-extraction of view is allowed
 // ('src' equal to 'dst') as a mean of fast-cropping (but note that doing so,
-// the original dimension will be lost).
+// the original dimension will be lost). Picture 'dst' need not be initialized
+// with WebPPictureInit() if it is different from 'src', since its content will
+// be overwritten.
 // Returns false in case of memory allocation error or invalid parameters.
 WEBP_EXTERN(int) WebPPictureView(const WebPPicture* src,
                                  int left, int top, int width, int height,