In the center of the land of Mirath, there is a tower with a mirror known as the 'Mirror of Inversion'. This mirror has the magical property of inverting the handedness of anything reflected in it, such that an object held in the left hand appears to be held in the right hand in the reflection, and vice versa; this effect also applies to written text making it appear backward. The land of Mirath is currently celebrating the Festival of Shadows, where each citizen, holding a lit candle, seeks to have their shadow captured in the mirror to gain a year of good luck.

Two friends, Zephyra and Einar, decide to test this mirror's properties. Zephyra has a unique birthmark on her left cheek, and Einar holds a sign with the word "LUCK" clearly written. They stand in front of the Mirror of Inversion with the setting sun directly behind them, casting their shadows on the mirror's surface.

A curious observer, named Tendaji, stands off to the side, watching the scene unfold. Tendaji is particularly interested in whether Zephyra's birthmark and Einar's sign will be affected by the mirror's magical properties in their shadows, given the fact that shadows are merely silhouettes without discernible handedness or readable content.

As the sun begins to set, a local storyteller, Yara, noticing the participants' experiment, approaches to regale them with tales of the mirror. Yara has been researching the legends and has potentially important information that could alter their understanding of how shadows interact with the Mirror of Inversion.
As Zephyra and Einar position themselves in front of the Mirror of Inversion, their shadows are cast onto its surface due to the light from the setting sun. The mirror's magical property is to invert handedness, a property usually visible only in the way reflections normally work, but with an additional twist--it also inverts the handedness of things which typically do not have handedness, such as handwriting, making them appear backward.

First, we consider Zephyra's birthmark. Ordinarily, a reflection would indeed show the birthmark on the opposite cheek but considering the way shadows work, Zephyra's birthmark would not be affected by the mirror's handedness-inverting properties since shadows do not capture such details. Instead, Zephyra's shadow would show a silhouette without any visible birthmark because shadows only capture the outline generated by blocking the light and not the surface details.

Now, regarding Einar's sign with the word "LUCK," normally, if he were to look directly into the mirror, the handedness inversion trait would cause the text to appear backward in the reflection. However, if we think about the shadow of the sign, it would simply be a silhouette of the sign's shape on the mirror's surface. The text on Einar's sign could not be read through the shadow on the mirror because, like Zephyra's birthmark, shadow silhouettes do not convey text, patterns, or handedness, just the outline.

As for Tendaji, he would only observe the shadowy figures of Zephyra and Einar against the mirror without any distinct features, such as the birthmark or the letters, due to the nature of shadows which lack detail and only present the form of an object blocking the sun's rays.

Finally, Yara's information might contain some revelatory detail such as a legend that the Mirror of Inversion also reveals hidden truths or inner natures when a shadow is cast upon it. If this were true, then perhaps Zephyra's birthmark or the text of Einar's sign might manifest in some inexplicable way within the shadow, despite the usual properties of shadow projection. However, based on the magical constraints as we know them, Yara's intervention would be speculative and separate from the logical reasoning established herein. Without Yara's potentially mythical revelations affecting the Mirror of Inversion's known properties, Tendaji and other witnesses should expect to see normal silhouettes of Zephyra and Einar in the shadows, unaffected by the magical property concerning handedness inversion.