The analyses of a text #3

The narrator recalls his adolescence.
He is an apprentice for the lawyer Mr. Spenlow.
His grand aunt and her best friend came to London after her going bankrupt.
He visited Doctor Strong's house in Highgate, to get the job of secretary for him, who was the head master of the school the protagonist went to.
When he was having breakfast with Doctor Strong and his wife Annie, Annie's cousin Mr. Jack Maldon came to the house on a horse.

'Have you breakfasted this morning, Mr. Jack?' said the Doctor.
'I hardly ever take breakfast, sir,' he replied, with his head thrown back in an easy-chair. 'I find it bores me.'
'Is there any news today?' inquired the Doctor.
'Nothing at all, sir,' replied Mr. Maldon. 'There's an account about the people being hungry and discontented down in the North, but they are always being hungry and discontented somewhere.'
The Doctor looked grave, and said, as though he wished to change the subject, 'Then there's no news at all; and no news, they say, is good news.'
'There's a long statement in the papers, sir, about a murder,' observed Mr. Maldon. 'But somebody is always being murdered, and I didn't read it.'
A display of indifference to all the actions and passions of mankind was not supposed to be such a distinguished quality at that time, I think, as I have observed it to be considered since. I have known it very fashionable indeed. I have seen it displayed with such success, that I have encountered some fine ladies and gentlemen who might as well have been born caterpillars. Perhaps it impressed me the more then, because it was new to me, but it certainly did not tend to exalt my opinion of, or to strengthen my confidence in, Mr. Jack Maldon.
[David Copperfield by Charles Dickens]
1. I'd like to know if "natural/ common" is omitted after"considered."
2. I don't think "such success" is in an apposition to the "that" clause.
So I was wondering what "displayed with such success" means
Thank you in advance for your help.