According to the narrator, in what ways was London "altered" or changed?

From the text:

"The face of London was now indeed strangely altered: I mean the whole mass of buildings, city, liberties, suburbs, Westminster, Southwark, and altogether; for as to the particular part called the city, or within the walls, that was not yet much infected. But in the whole the face of things, I say, was much altered; sorrow and sadness sat upon every face; and though some parts were not yet overwhelmed, yet all looked deeply concerned; and, as we saw it apparently coming on, so every one looked on himself and his family as in the utmost danger. "