There is a long, thin, rubber-y line wrapped around/connected to the water line pictured below.
Other angle:
The piece in question is loosely hanging via a zip tie on my main water line about shoulder height and can be moved up/down easily.
Anything is an antenna if you don't care about SWR lol.
Seriously though, us amateur radio operators have turned rain gutters, chain link fences, and bridges into antennas, among other things. If it's metal and the swr can be controlled with a tuner of any sort, it's an antenna.
Is it going to be great on every wavelength? Absolutely not. But it will work.