The mirror uses two characters to describe itself: the woman, and the lake (metaphor).
First, the mirror (personified) imagines itself to be a lake, witnessing everything that hovers over in nature. Just as when the mirror is in the empty room reflecting what is seen here, the lake reflects what can be seen in the sky, and anything that is within the distance of the reflection (scientifically). This reflection is just as true and genuine as that reflection that the mirror provides in the empty. Additionally, the mirror uses the woman (at the lake) to describe itself as well. As the lake provides genuine reflections, the lake describes what can be 'seen' when the woman looks in to the lake: (first) a young girl who faces challenge but brings a positive outlook to life and a 'feeling' of hope to the lake, and (second) a old woman struggles to maintain hope in this lifetime, metaphorically using candles and the moon to back the assumption that brighter situations could never possibly
occur.
Candles (assuming that they are lit) and the moon both reflect bright light. In this instance, the moon refers to candles and the moon as liars because they make many situations seem brighter and more vibrant than they really are. In fact, one can even interpret that the mirror 'feels' as though ideal of this conceptualized brightness from the candles and the moon is a fallacy. The mirror 'feels' as though the reflection of anything (including the background images in the mirror as well as the light from the moon and candles) should be realistic and practical, and should be a true demonstration of what can be 'seen.' The mirror 'feels' as though the light reflected from these two aspects does not show the practical side of life, and therefore refers to both as 'liars.'