GR translation: that stateless lascar across his own mirror-glass

[Mike Jing]

P35.3-20   Pirate wonders if Mexico isn’t into yet another of the
thousand dodgy intra-Allied surveillance schemes that have sprung up
about London since the Americans, and a dozen governments in exile,
moved in. In which the German curiously fades into irrelevance.
Everyone watching over his shoulder, Free French plotting revenge on
Vichy traitors, Lublin Communists drawing beads on Varsovian
shadow-ministers, ELAS Greeks stalking royalists, unrepatriable
dreamers of all languages hoping through will, fists, prayer to bring
back kings, republics, pretenders, summer anarchisms that perished
before the first crops
were in . . . some dying wretchedly, nameless, under ice-and-snow
surfaces of bomb craters out in the East End not to be found till
spring, some chronically drunk or opiated for getting through the
day’s reverses, most somehow losing, losing what souls they had, less
and less able to trust, seized in the game’s unending chatter, its
daily self-criticism, its demands for total attention . . . and what
foreigner is it, exactly, that Pirate has in mind if it isn’t that
stateless lascar across his own mirror-glass, that poorest of exiles.
. . .

According to the Wiki, this refers to Roger Mexico, is that correct?
What is "his own mirror-glass" referring to?