This is a simile that emphasizes how bright in appearance the angel was. AT: "was bright like lightning" (See: [[rc://en/ta/man/translate/figs-simile]])
This is a simile that emphasizes how bright and white the angel's clothes were. The verb "was" from the previous phrase can be repeated. AT: "his clothing was very white, like snow" (See: [[rc://en/ta/man/translate/figs-simile]] and [[rc://en/ta/man/translate/figs-ellipsis]])