To me it seems there is a swinging 45° mirror about where that white dot up front is, projecting the image via a 2nd oblique mirror and further optics to produce a small aerial- or groundglass-image that can viewed via that oblique binocular or goggle.
By substituting an ordinary lens for the special [stereoscopic] lens of this camera one obtains a camera for conventional photography which offers all advantages due to the improvements which form the subject of this invention.