This is the standard Australian Brilliant Uncirculated coin set for the year. It contains all the regular circulating denominations.
The Royal Australian Mint says about this year's set:
"This 2020 Uncirculated Six Coin Year Set, features the sixth and newest effigy of Her Majesty Queen Elizabeth II on all of Australia’s six circulating coin denominations.
The new effigy by Jody Clark, depicts the Queen wearing the Royal Diamond Diadem which she wore to her 1953 Coronation. A highly collectible set for coin enthusiasts and numismatists."
Coins dated 2020 were minted and released in October 2019 in Royal Australian Mint sets. Note that these mint sets refer to Jody Clark's portrait of the Queen as her "6th Effigy", which takes into account her effigy by Vladimir Gottwald issued (in Australia only) in 2000.