The SEFER MITZVOT GADOL (Great Book of Mitzvot); SMaG; written by one of the Rishonim; Rabbi Moshe of Kutzi; writes (negative Mitzvot #65, "39th melacha of carrying from one domain to another" paragraph beginning "Aval Makom Patur") that it does not actually mean that they adjust their loads. What it means is that they place a burden or package on the place that is less than 4x4.

They did not carry something 4 amos in the public domain. That would constitute a Torah prohibition. What happened was that there was an object lying there, less than 4 amos away from the small place that is less than 4x4, and the people of the Reshus Harabim moved that object, from its original place in Reshus HaRabim, onto that small place.

Good Shabbos

Dovid Bloom

Follow-up reply:

I heard another possible way of explaining ???? ???? ????? ......???? ????; which literally means to adjust the loads on their shoulders.

This is based on the Gemara below 84b ?????? ?????? ???? ?????? ??????.

Rashi explains that on weekdays, people walking in the street are accustomed to place their hats and cloaks on this platform. Clearly one is allowed to wear these items when walking in Reshus Harabim and occaasionally one wishes to take them off. The place less than 4x4 tefachim is convenient for doing so.

KOL TUV

Dovid Bloom