Well, it seems so. Besides this, I cannot give a more logical explanation.

Here is the difference between eval and bind:

Data-binding expressions are contained within

<%#

and

%>

delimiters and use the Eval and Bind functions. The Eval function is used to define one-way (read-only) binding. The Bind function is used for two-way (updatable) binding. In addition to calling Eval and Bind methods to perform data binding in a data-binding expression, you can call any publicly scoped code within the

<%#

and

%>

delimiters to execute that code and return a value during page processing.

 

....and I have done an experiment: instead of  <%# Bind("Description") %>      I have written   <%# Bind("aaaaa") %>, and is not working. So.....this is the only explanation :)