diff --git a/doc/fig/RPN_fig.jpg b/doc/fig/RPN_fig.jpg
index a89179f0b2e..3ece698589b 100644
Binary files a/doc/fig/RPN_fig.jpg and b/doc/fig/RPN_fig.jpg differ
diff --git a/doc/rst/source/RPN_info.rst_ b/doc/rst/source/RPN_info.rst_
index bedeb006017..d63b0795dab 100644
--- a/doc/rst/source/RPN_info.rst_
+++ b/doc/rst/source/RPN_info.rst_
@@ -6,4 +6,4 @@
    which is a post-fix system for mathematical notion originally developed by
    `Jan_Łukasiewicz <https://en.wikipedia.org/wiki/Jan_Łukasiewicz>`_ (right).
    Here, operands are entered first followed by an operator, e.g., "3 5 +" instead
-   of "3 + 5 =".
+   of "3 + 5 =" (photo courtesy of John W. Robbins).