WiFi antenna's shield
Yes, this is normal.  Note that the shield and the center conductor are not connected at the same place.  The current path between the two points is a significant fraction of the wavelength, so this is perfectly plausible for a antenna.

When trying to understand antennas, you can't think in DC or viewing them as lumped systems.  Two points 1/4 wavelength apart, even if shorted DC-wise, are very different connection points.