This TV Aerial lookalike is perhaps best described as a collective quantity of aluminium prongs laid out on a length of square aluminium tubing, one thing is for sure and that is, it's definitely not a functioning TV Aerial, despite what it looks like.
Amazingly there is a dipole in which the TV coax connects and perhaps this is the only functioning part of this aluminium assembly. Saying that it has provided TV pictures for some years in a home I visited today (22nd December 2015) in the St Peter's area of Worcester albeit with intermittent loss of HD channels.
With a clear line of sight towards the Malvern TV transmitter from my customers roof top, I know from experience that even if you were to waft a simple metal coat hanger or indeed any short length of metal wire from a rooftop that's in close proximity to a TV transmitter it will produce a signal and TV pictures.
If you look at any TV Aerial of this type (known as a "Contract Yagi") you will notice that there is normally a minimum of three different element sizes which are then spaced differently across the length of the boom, the element size and spacing being absolutely critical to the correct functioning of the TV Aerial. If you look closely at this lookalike you will notice that the element sizing and spacing are all uniform.
In my 26 years installing TV Aerials I've only seen a handful or so of these Aerial lookalikes which were sold to unsuspecting DIYers by the large multinational DIY retailers. As their pricing would have been very appealing to anyone looking for a TV Aerial I would guess that there may have been many thousands of them sold over the years.