That box looks like a FTA box that also does IPTV, but it isn't dual tuner for IPTV. You could use the HDMI and composite video simultaneously, I guess, but it will be the same channel. (It won't do dual tuner for satellite either, you need separate tuners for that).
I guess its possible to make a box that will simultaneously display different IPTV streams, but I think that a market for that would be pretty small.