Hi,
Believe me, they sound as good as they look!
I've only connected to B&O kit, but you can definitely connect to non-B&O using the phono jack. Unless I'm mistaken (and there are far more experienced users of this forum than myself), you need to connect left channel from the audio source to one Beolab 6000 and right channel to the other. Do you have red and white, L & R, "audio-out" phono sockets on the rear of your TV? If so, you just need a straight-through male-to-male phono cable for each speaker, one off to the left and the other to the right. A 'Y' cable like you show is for splitting the same signal whereas you want left/right stereo channels.
BL 6000s are active (have built in amps) so need to be plugged into the mains to be powered, but most importantly there's a small switch on the base of each speaker with L•R•LINE. You must slide the switch to LINE.
As I said, I stand to be corrected, but I'm pretty sure that's all you have to do.
Rob