Since currently there is no way yet use the magnetic input in Web VR on the Cardboard V1, an option would be to use the "fuse" feature, i.e. to simulate a "click" when you look at an object for a certain time. The default <a-camera> cursor and the default cursor component have this feature it switched off.
The fuse attribute <a-camera position="0 1.8 0" cursor="fuse: true; maxDistance: 100; timeout: 500"></a-camera> works unreliable on Chrome. More investigation needed.
Since currently there is no way yet use the magnetic input in Web VR on the Cardboard V1, an option would be to use the "fuse" feature, i.e. to simulate a "click" when you look at an object for a certain time. The default
<a-camera>
cursor and the default cursor component have this feature it switched off.