I have made a new doctype 'speaker' and am putting it into a repeater so the author can add as many speakers to the 'event' page as they wish.

It's mostly working except for the image. I added a field type 'file' to the form, allowing the author to upload a mugshot. This works OK in Page mode - I get my image uploaded and I can see it's filename and even preview it:


but what I get output on the page is nothing more than a GUID:

<div class="speaker-pic">
<img src="286155c5-d7ba-4219-b885-8fa4c73f8cc7">
</div>
<div class="speaker-name">Zachary Reiss-Davis</div>
... 

My transform looks like this:

<div class="speaker">
  <div class="speaker-pic"><img src="<%# Eval("Pic") %>"/></div>
  <div class="speaker-name"><%# Eval("Name") %></div>
   ...

Two questions:
1] why am I getting a GUID instead of a filepath? and, more broadly
2] from the point of view of a content author, is this "file upload" the optimal/preferred way to point a form at an asset? Perhaps it could it be uploaded to a media library first, or something like that?