For those who don't know, the phrase "let them eat cake" is commonly attributed to Marie Antoinette, the Queen of France in the late 18th century. However, there's no concrete evidence she actually said this. The phrase is used to portray her as out of touch with the suffering of the French people during a time of widespread poverty and famine.
Having the phrase "let them eat cake" in a super luxurious house is incredibly insensitive because it symbolizes a callous disregard for the struggles of those less fortunate. It's a reminder of the kind of detachment and insensitivity that can perpetuate social inequalities and exacerbate class divides, which is particularly tone-deaf in a setting of opulence.
It's interesting to note that she was widely hated even at the time though not because she was a rich noble, but because she was austrian. So it's possible the phrase is a fabrication that stuck.