I can just imagine their report back to the mother ship. There would be some debate that Earthlings' worship their "wheeled transport vehicles". After all they have them as idols raised on rock like platforms in their yards. Yet, they do not clean them nor seem to take care of them, often operating them with pieces missing and evidence of damage to the exterior. In their homes they have pieces of pottery decorated with colorful pictures of vehicles sporting of numbers and a black and white flag scattered about on tables and shelves and adorning their walls.
They inhabit metal modules divided into several living spaces. Often the floor is covered with a matted green fibrous material. The main rooms of most modules include at least one throne type chair reserved for the head of the family unit. Male Earthlings are fond of their metal defense devices that are used to kill other lower forms of life. Then the heads of those prizes are displayed in the living modules - perhaps as idols.
Earthlings consume mass quantities of a grain based beverage and white flat pieces of grain based food smeared with a white congealed product topped with slices of a round flat pink food that contains some animal product. Other consumables include bags of thin flat pieces of a tuber type plant, large vessels containing two toed feet of some lower life form preserved in a pink liquid, and other large vessels of whole poultry ova also preserved in pink liquid.
And one last mystifying point of these Earthlings - they are in search of a god named Elvis that lore said died many years ago, but many have faith still exists among them. Large images of his likeness on a black napped background can often be found adorning the walls of their living modules in a very visible place.
Over the years, having come into contact with many sophisticated space ships supposedly launched from this planet, they would be confused. But then after their visit to our planet, no doubt their only conclusion could be that Earthlings are searching the heavens for this this God named Elvis.