http://digitalcollections.smu.edu/cdm/singleitem/collection/mex/id/678/rec/4

“Train of pack burros in Mexico”

Calling the pack of a burros a “train” implies the animals as a means of transportation. However, if they are for transportation, why the man walking in the field not riding a burro? He could just be walking in order to keep the burros heading in the correct direction, or he could be of lower rank/class. The burros in the field have saddles on their backs, suggesting they are meant for riding. Also, the referring to the burros as a train sheds light on the pre-European technology of the region – lacking in railways. Therefore, burros a cultural necessity in terms of transportation, for the time being anyway. Remaining questions: where are they heading? what is the difference between the man on the burro and the man walking?