The chart indicates that (generally) gold is hedge against the rising prices of homes in the UK between the early 1950's and today. To wit:
The chart begins in the early part of the 1950's. At that time, gold was given an index of 100 as was the price of a house in the UK (which is problematic, as you will see).
Soooo....in 1953ish both the real estate home price and the gold price were indexed the same: 100 (since that is the starting date)
From the early 1950's up until about 1968 or so, the price of gold and the price of UK houses remained similar: If you look at the slope of the lines between 1953ish and 1968ish they are identical.
What does that mean? (this is why you should have paid attention in math class). It means that the value of both gold and real estate were rising at the same rate (hence the same slope or rise/run). As the price of homes went up, the cost you pay in fiat or gold followed in lock-step. Gold or fiat...made no difference they were the same (relative to house prices, per this chart).
But, take a look at 1973: Gold and home price in fiat now diverge dramatically. The gold slope becomes negative, while the slope of the house bought with fiat goes positive.
Now, the house will cost you more in Fiat, but less in Gold. Why is that news?
Because if you had 50 oz of gold (arbitrary number for demonstration) in 1973 and did NOT buy a house for whatever reason you could buy the same exact house 10 years later for the same amount of gold In other words, your gold has not lost value (relative to housing in UK).
If, on the other hand, I had 50k in fiat and waited the same 10 years, I would now need about 210k in fiat to buy the same exact home that I looked at 10 years previously.
Of course there are many, many other factors that need to be included in a calculus of this level but the idea is to show you how awesome gold is why you need to buy it from the seller ๐
The reality is much more complex, but one that sticks out to me is what data was used to generate the UK home values ? Median? Mean? Was the general increase in home sizes/amenities taken into consideration? In New England where I live, homes from the late 1960's and 1970's can't be compared to homes build in the 2000's due to size increases and other factors. They are naturally going to be more expensive since they are so much better. You could make your own chart using info from you local area and get more accurate info. Where I live I use median home value per zip code and try to normalize for location and type/size of house.
The price of gold in the 1950's up to 1974 is also a bit problematic to me since well, many of us couldn't legally own it ๐
Remember: People can cherry pick data to infer any conclusion they want. You need to understand the biases of those creating the chart and really think about what they are trying to prove and why ๐