Definitions:
a surface, typically of glass coated with a metal amalgam, which reflects a clear image

a site on a network which stores the contents copied from another site

(of a surface) show a reflection of

correspond or be similar to (another thing)

display content from (the screen of a computer, phone, or other device) on another screen, usually via a wireless connection

keep a copy of the contents of (a network site) at another site, typically in order to improve accessibility