The marathon hires these photographers, see, who take bajillions of pictures along the marathon route. Then some poor schmuck has to look at all the pictures and identify which bib numbers are showing in them. Then you can use your bib number to find your photos online and
And here are two of my expensive new pix: me crossing the finish line (looking surprisingly awake and alive and happy) and me smiling like the proud parent of two gifted quadriceps at the finishers' photo op. Enjoy!