A Chabadnik with his fringe flying, he was in such a hurry!
We posted about the cleaning frenzy Israelis get into the week before Passover, but in general everybody is frantically trying to get all the preparations done before Pesach begins.
I assume the Chabad man was wheeling his little stand (with the picture of the Lubavitcher Rebbe) to a strategic place in or near Machaneh Yehuda market (this was three days ago).
Probably he was going to help people sell their chametz, letting them sign a power of attorney form so that Chabad could sell (actually lease) all their not-allowed-during-Pesach-week food to a non-Jew.
I am not frum enough to be able to explain this well, so if you really want to know, please see the "Chametz Wizard" for a short and authoritative explanation.
Furthermore, in the Age of the Internet, Chabad now helps Jews all over the world sell their chametz online!
P.S. Here is the definition of chametz, from Chabad:
"Chametz is "leaven" -- any food that's made of grain and water that have been allowed to ferment and "rise." Bread, cereal, cake, cookies, pizza, pasta, and beer are blatant examples of chametz; but any food that contains grain or grain derivatives can be, and often is, chametz. Practically speaking, any processed food that is not certified "Kosher for Passover" may potentially include chametz ingredients."
Chag sameach/happy holiday and Shabbat shalom!