https://help2.talktalk.co.uk/tv-demand clearly states:
Head directly to the Player: Press the YouView button, select Players & Apps and take your pick from the best On Demand players like All4, BBC iPlayer, ITV Hub & more.
Both players are also featured on the packaging of the youview box.
NEITHER ITV nor All4 players are installed or installable.
The information on the website as well as the packaging are misleading advertisements.