We can't be exactly sure what the Egyptians were wearing on top of their heads in these paintings, but archaeological evidence suggests they were probably perfumed cones made of wax or fat. It is mostly women that are depicted wearing them, but men of all social statuses, including servants, are also shown wearing them to parties. They wore them on the tops of their wigs, where they would slowly melt over the course of the evening. Women today often put oils in their hair to give it moisture, but this is something else. For one thing it must have been a pretty unpleasant sensation having a big lump of wax dripping down the back of your head, and secondly it must have ruined the wig.
