PaExec -i not showing on RDP session

I have an application where I used psexec -i <session#> to remotely execute a UI-based application on a host and converted it to use paexec but am seeing a difference in bahavior that I'd like to understand and address.

Specifically, I am opening up a remote desktop connection to the remove host, then executing qwinsta on that host to determine the session number (usually "2").

I then execute psexec/paexec with -i using the session number returned by qwinsta. My command line would look something like this:

paexec.exe \\10.1.1.44 -accepteula -dfr -u remotehostname\remoteuseraccount -p password -i 2 -w c:\temp c:\temp\MyApp.exe <arguments for MyApp>

If I use pSexec, the app runs and it's UI is shown in my Remote Desktop session. If I use pAexec, the app runs (I can see it in the task list and it's console output shows it's working), but it's UI is not shown in my Remote Desktop session and I can't figure out where it's UI is being presented.

Part of the application I'm attempting to run (a remote testing harness) attempts to take screenshots of the desktop while the app runs. With pAexec, all I get is black screens, and I assume this is related. I'm trying to understand where the UI is running so that I can address the screenshot issue.

Windows remotes that this is the only session currently active on the host. This is true for Windows7, Windows Server 2012, and Server 2008 (the remote environments which I'm currently running).

Can you provide some insight as to where the UI is actually running, and what, if anything, I can do to make it run in my Remote Desktop window?

Note: The remote app interacts with the desktop and other running apps (which it starts) using the Windows AutomationUI framework. These interactions are working (ie: it's finding the UI elements for the apps), so I know the app is successfully running on some desktop session -- it just doesn't appear to be the one I'm watching. The app is running under the user account I provided in the command line.