Justice is identified by scales and a sword, and the two are a complete statement of the classical definition on their own. The scales weigh the competing claims, which is the discernment half of rendering to each what is due. The sword enforces the finding, which is the half without which the weighing is only an opinion. Both are much older than Christian iconography: they belong to the Egyptian judgement of the dead, to Themis and Dike in Greek use, and to Roman Iustitia on the coinage.
The blindfold is not. It arrives late, in the fifteenth and sixteenth centuries, and it arrives as an insult. The earliest well known appearance is a woodcut in Sebastian Brant's Ship of Fools of 1494, where a fool ties the cloth over Justice's eyes so that she cannot see what is being done in her court. Only afterwards, over roughly a century, did the blindfold turn into a compliment and come to mean impartiality rather than blindness to corruption. The reversal is complete enough that most people now assume it was always the point.
That history is worth knowing because it is a rare case where an emblem's meaning can be watched inverting in the documentary record.
The atlas draws the scales with the sword, which is the attested classical pairing and the one that carries the definition the tradition actually gives. The blindfold is recorded here rather than drawn.