I can imagine this whole thing as though it were from a Coen Brothers movie, though I'm thinking something more Hudsucker Proxy than anything else.
A grainy black and white shot, the camera starts off high over the city, snowflakes falling past the lens. The city is a grid of black and grey, dark and unfriendly. The soundtrack is a choral version of Carol of the Bells.
Camera slowly zooms in on the sidewalk, we can start to make out a lump in the otherwise pristine snow. As the camera comes in closer we can see that it is a Bag Lady, strugling to take breath, but evidently still alive as we can just make out the steam from her breath.
The camera pans upwards and moves backwards, keeping the Bag Lady still in shot at the bottom of the frame. The top half the the shot is now the glass front of the dinner. We can see inside the gaily decorated dinner, the ornament covered tree on one side, the tinsel edging of the diner bar.
There is a family in the dinner, two middle aged parents and their eight year old daughter. They are kneeling on the floor of the dinner, heads bowed as if in prayer. Three men stand behind them, their faces hidden behind their keffiyehs, each man is holding a scimitar with the tip of the blade resting on each victim's left shoulder.
We see a tear roll down the little girl's face.
As the singing reaches its cresendo the men pull their swords back. At the climax of the song the blades slash down wickedly, severing heads from the bodies. Simultaniously we see the Bag Lady let out one final breath and her whole body relaxes as she slumps, still and dead.
As the scene fades to black, the singing ends just in time for us to hear the soft thud of the bodies falling forwards on to the floor.