Mmmm, a Memera 2000, I think. Installation looks good. Doesn't look worrying. Howevere, I can't read the rating on the MCB for the cooker. Should be 32A (and probably is) but if not you can easily get a new Memera MCB fitted. You should have switched the cooker MCB off since you have no cooker attached and you have taken the plastic cover off the outlet (don't trust switches, as a matter of habit, although yours looks pretty new and I have no reason to doubt it).
Connection to the outlet plate looks straightforward, as easy as wiring a plug. the cable sheathing has to continue under that clamp. Don't thread the cable through any cutouts in the steel oven frame unless they are protected by a plastic or rubber grommet (you can buy these for pence in 20mm and 25mm sizes), as the cut steel edgdes can chafe or cut through the cable sheath and insulation (bang).
The cooker terminals - pic is not clear, but I think there are square clamps under the nuts on those screwed pillars? Might be like square washers with the edges bent down to stop the wire slipping out. I can't see the earth terminal, though. There must be one (or more) and you have to slide green and yellow sleeving over the (bare) copper earth wire in your new cable. There ought to be connection instructions in the handbook. There will be a cable clamp on the cooker, again, this must grip the cable sheathing. There must be a plastic cover over that terminal block.
If the connections are low down, you don't have to use heat resisting flexible cable, but it wouldn't hurt. Solid core T&E is cheaper but stiff. Allow enough slack for pullling the oven out if needed. You can use 6mm cable if you can't find 4mm, and remember to buy some green and yellow sheathing (very small amount) to cover all the exposed copper earth wire that isn't in a terminal.
Strip back just enough insulation to give a good depth of conductor in the terminals, but not leave exposed copper.
BTW I see a gap in that consumer unit next to the RCD, you need a plastic blanking piece in there as it gives access to live parts. Ask your nearest electrician's supplier for a Memera 2000 MCB blank (not a 2000 AD) while you're buying the cable and G/Y sheathing. Turn it off before touching it.
Anybody, have I forgotten anything?