What do the illusory marks symbolize in Madame Hermet?

The illusory marks symbolize aging..... the lines of life.

Did she, like so many others, gaze for hours and hours at her skin, once so fine, so transparent and free from blemish, now beginning to shrivel slightly, to be crossed with a thousand little lines, as yet imperceptible, that will grow deeper day by day, month by month?