With the VSS-1 system, the video received from a remote Skype video call shows on the big screen in conference room . . .

Here’s Skype’s description/definition of  the video resolution of the three types of video cameras that Skype can support and that will appear on the conference room screens –

HD-capable, High Quality & Standard Quality.

Here’s the link to those three webcam options with Skype certified cameras –
http://shop.skype.com/webcams/?cm_mmc=affiliate-_-commission_junction-_-banner-_-webcams_page_pid%3D3315155

 The link describes the image quality that you could receive with the VSS-1 system:

1. HD-capable - Make Skype video calls in Hi-Definition – in geek-speak that’s 1280 x 720 pixel resolution at up to 30 frames per second.

2. High Quality - See every smile and wave in High Quality Video – in geek-speak that’s VGA quality with 640x480 pixel resolution at up to 30 frames per second. Great because: You can increase the size of your video call window without losing picture quality.

3. Standard Quality - If you’re just starting out these webcams are perfect. Great because: The simplest and most cost-effective solution for making video calls from Skype.

So one of the key factors affecting video quality is the camera that’s being used at the remote Skype sites.

Another key factor is the Available Bandwidth on the link between the sites.