SP2013 Drag Files Here does NOT show up in IE9 with Office 2010

As always, SharePoint provides daily learning lessons.  Today I noticed that the "or drag files here"  control didn't show up on computer where I was doing a demo of our new SharePoint 2013 environment.  The machine in question is running Windows 7, Internet Explorer 9 (32-bit) in Compatibility View, and running Office 2010.

I opened the same site in Firefox and was able to demo the drag and drop feature without issue.  But this got me to questioning what was causing the problem (was the browser or the office version?)

So I came back and looked at 2 machines in the office. Same build and updates on IE running on both machines. Same Compatibility and Internet Options settings.

I tried removing Compatibility View and clearing browser history on IE, but this made no difference.

Here's what the machine running Office 2010 looks like: 

The machine running Office 2013 shows the same site like this:

I was logged on with the same credentials/permissions to the site both times. I was really stumped about this until I posted a question in the community and got a link to Jasper Oosterveld's blog posting about this (see link below).  Basically what Jasper states is that Office 2013 is required for the drag and drop feature to work IF you are using IE8 or IE9.  Other browsers, such as Chrome, Firefox, and IE10 the drag and drop feature works without Office 2013 installed.

Thanks to Trevor Seward for providing this URL link:

http://www.jasperoosterveld.com/2012/08/sharepoint-2013-drag-and-drop.html