The icon and the legend are two different things, I believe. A screenshot would definitively help hehe But the icon means that either the plug-in required to watch the video is not supported by your device (if the site uses a Flash-based video player, that's most likely the reason since Flash support for Android devices was dropped some time ago) or, if the warning text is any indication, the CONTENT is being blocked by some filter in your network. This could be the Juniper firewall blocking a specific port, which would let you browse the site but not stream the video content for example.
Try this: Connect a PC to the same network as your tablet. Does it show the same message? If not, then the culprit is the plug-in not being compatible with tablets. If it shows the same message, then you'll know it's a problem with the network blocking that specific content.