What is this component on a satellite TV STB?
Looks like a PCMCIA connector, which is ordinarily used for CableCard on cable STBs. I've not seen one on a satellite box however (I'm in the US - DirecTV and Echostar boxes don't use PCMCIA, so that's why I haven't seen one.)

What's the model of the box? (you answered.)

EDIT: A cursory search for this box doesn't show the PCMCIA slot specifically. That said, sometimes in STBs the PCMCIA card holds the conditional access hardware, which itself has an ISO7816 card inserted for the keying material. I suppose this is an optional interface on this box so if it needs to support a conditional access scheme that the internal chip doesn't support, the provider can use the external type instead.

The way these schemes work is that they take the encrypted tuner feed and circulate it through the card, where it is decrypted, then re-encrypted using local keys supplied by the ISO card, then sent back to the system chip where it is decrypted once more and finally decoded for presentation.

This way, the data are never 'in the clear' except inside the system chip where it's not visible to prying.