You mean this
kind of thing?
I have the highest regard for Takeda Sensei, but I understand that in his school (Aikido Kenkyukai) ukes are encouraged to be extremely responsive, for better or for worse. In this clip, at least, I see lots of beautiful flying through the air, but a shortage of actual attacks that you would have to get out of the way of...
There's plenty of flying about, but I wouldn't characterise it as beautiful...
Perhaps the guy means like Chrisitan Tissier's ukes - that's what comes to my mind when I hear 'Beautiful Uke(mi)':
...I hasten to add that I love Christian Tissier's style.