GR translation: view finder

[Mike Jing]

V3.18-20, P3.18-21   Only the nearer faces are visible at all, and at that
only as half-silvered images in a view finder, green-stained VIP faces
remembered behind bulletproof windows speeding through the city. . . .

The wiki suggests here "view finder" refers to some kind of handheld 3D
slide viewer such as the View-Master (
https://en.wikipedia.org/wiki/View-Master ). However, these devices do not
appear to be commonly called "view finders". The term, in all spellings (view
finder, view-finder, viewfinder), overwhelmingly refers to the viewfinder
of a camera. And half-silvered mirrors are used in at least some of
these mechanisms.
It seems to me that's more likely what's being referred to here, am I
correct?