What does the Note Taker mean by 'the noble architecture of these noble columns'? Why noble?

The author is referring to the nobility (granduer) of the place Eliza sits and the fact that he doesn't even believe her worthy to be there peddling her flowers. In this context noble would be defined as grand, imposing, magnificent, of superior quality; he's talking about a structure here....... and he's demeaning Eliza, who he compares to a squashed cabbage leaf.