WM Recorder in the PRO mode captures packets coming to your Windows Media Player, so content providers see you using a regular (embedded) Windows Media Player.

And WM Recorder in the ADA and URL recording modes (like any other streaming video recorder) tries to pretend to be Windows Media Player. Can it be seen from the server side? Sometimes yes. Especially if you download multiple streaming videos from the server.

Also your content provider can be cautious if you record too many streaming videos.

Please note that other players (for example: VLC Player, MPlayer) also allow you to watch Windows media streams.

Related thread:
Risks to Recording...? Can I be detected and sued for capturing streaming lectures?