Clarify changelog item.
@@ -11,6 +11,9 @@ Storage
This should result in large performance speedups and lower memory usage when
uploading or downloading a large file with a mismatching chunk size.
+
+ Keep in mind that this only affects code paths where the function is called
+ with ``fill_size=True`` argument (such as in the S3 driver, etc).
(GITHUB-1847)
[Tobias Biester - @Tobi995]
