It radiate from both (radiator and feed line). In other words, microvert antenna works like a small dipole.
In my case last weekend i just build another microvert wich has an irradiating tube of 38 mm in diameter. The antenna was placed at 8 meters above the ground and now is working like a champ, cause most of my signals are 59 plus and even plus 25 dB. My dipole and end feed antennas gets a high electrical noise on 40 meters.Microvert thanks to his low angle (19°), does not pick up that noise, allow me to listen stations very clear.
In conclusion you can build this antenna and to get a good performance from it, is very important that the antenna get at leats 1/4 lamda or more above ground.
It's been proven many times that nearly all of the radiation from extremely small antennas is from the feedline, and not from the antenna "radiator" itself.