[6] The Desborough mirror, like that found at Bridlip, is in relatively good condition compared to other extant decorated examples, a number of which may be reproductions given the disparity between their high-quality design and relatively poor-quality execution.

[10][2] The reverse side is decorated with intricate curvilinear Celtic designs in the "Insular La Tène" style, including engraved spirals, crescent shapes and "trumpet" (three-sided) patterns.

This application of very small patterns required significant technical precision, and thus the final hatchings were most likely applied before the handle and tubing were attached, while the plate was held in a type of grip or vice.

[13] The plate's broad outline appears to be that of a lyre (a stringed musical instrument similar to a lute) with flanking coils and was probably initially laid out using a scriber and compasses.

Modern art historians generally agree that this inversion of positive and negative space was intended to invoke the way mirrors reverse the direction of any image at equal and opposite angles.