Magic moments - an old woman

Many years ago, I worked for a few months in a kibbutz. After a few weeks I was sent to work in the kitchens, washing dishes. Then this happened.

I am standing at a sink, scrubbing aluminium trays and stainless steel pots. The staff are mostly older women, in aprons and headscarves.
As I work, an older woman, with lined face but with black hair, seeming older than her years, comes over to collect a new pot.
She has short sleeves; her arm as she reaches past me is tanned above, with melanomic spots, and the underside of her forearm is paler.
It is marked by an ancient tattoo, a triangle followed by six digits.
I know what it means, I have heard of this but have not seen it before.
For a frozen instant, I pause, glance and raise my eyes to hers.
She sees the direction of my gaze and knows that I recognise the mark. She gives the faintest nod and a glimpse of a grin, then carries on with her work.
I hope I conveyed sympathy. She knows I know what it means.

But I know that I cannot truly understand. For she survived Auschwitz.