Mystery coolant leak

[Seatdownhere]

Over the past couple months I've noticed steam coming up from under the bonnet on the odd occasion, e.g stopping in traffic or at lights after driving for a few minutes. Changed coolant cap, pressure test didn't show loss in pressure, but still it happens. Today, I was able to stop and get out the car within a minute of it steaming, and I *think* I've pinpointed where it's coming from.
Could anyone please tell me what the hose in the photograph is called, and if it does indeed carry coolant? You can see that it's a bit wet, and below it i managed to get some paper and it was pink in colour.
The bottom of the image is the fan/radiator towards the front grille.

 

[Rusty2k]

That looks like the wiring loom for the alternator.

The coolant is probably being sprayed there from a leak in the radiator.

 

[Seatdownhere]

That looks like the wiring loom for the alternator.

The coolant is probably being sprayed there from a leak in the radiator.

Many thanks for this. Yep, giving that 'hose' a squeeze me me realise it wasn't a hose and I can feel the wiring inside.

Could there still be a radiator leak even if the pressure test showed up as not losing pressure?

 

[ZiggyEP3]

Shame you don't have the inspection camera that's in Lidl right now. Not tried one so don't know if any good either that or a phone on a selfie stick to have a look down there.

 

[Seatdownhere]

It started smoking quite badly today, whilst creeping up hill in traffic in the rain. It's worse when I'm moving slowly, but not sure if that's just because the steam/smoke just dissipates when going faster.
Managed to pull over and check, and it looked like it was coming from under that silvery metal plate (with the torx screw) in the original photo. Or the component with the pipes coming out of it, to the right. Anyone know what those are?

Can't find a diagram or labelled photo of the engine compartment, so having trouble knowing what those things are. Workshop-manuals website used to be good for my previous car, but only contain text for Leon MK2.