While I agree, the feedback I get from a session like that is useless:
"While you mentioned this during the demo, I noted:
1. Your state-drop down has only 3 entries.
2. There is a validation error
3. You get an error at the end.
Yup, that'll happen, and if you omit it entirely you can get comments going "I'm not seeing this field!".
Would it be better to show no progress at all until it's completely done? I know agile methodologies tell you to demo regularly, but I'm more and more under the impression that they are to provide progress feedback / reports to management.
I remember someone suggesting using deliberately crude and hand-drawn looking UI elements in the demo. That communicates to non-technical users that it's just a prototype.
"While you mentioned this during the demo, I noted: 1. Your state-drop down has only 3 entries. 2. There is a validation error 3. You get an error at the end.
We need you to fix this ASAP !!!"