Complex sentence: An alternative version of the instrument adapts a telescope, omits the object cell, and allows the observer to view current surroundings; the teleidoscope can transform a portion of any scene into an abstract repeating mosaic.
Split into simpler sentences: An alternative version of the instrument omits the object cell and allows the observer to view any scene through it, in the manner of a telescope. This version of the instrument can transform a portion of any scene into an abstract repeating mosaic.