These are rather famous heads - the children of Tsar Nicholar II, whose heads were shaved after a bout of measles.
I wondered about the reasons for this tonsural excess; a quick search found statements that it was done to relieve fever -
"I read about lots of people shaving their heads when they have measles back then. It seems that it was done for coolnes. High fever made people to have a very "hot" sensation at the head."- or to prevent transmission by fomites:
"In those days, after an illness like measles, scarlet fever, etc, had affected someone, their hair, clothes, toys, etc were burned to destroy the virus and ensure that no-one got re-infected. The girls all had VERY long hair and I suppose it was believed the virus could get stuck and incubate in the hair. So, the only way to ensure that the virus was no longer in the house was to shave off the hair and burn it."- or that it was for cosmetic reasons:
Their hair started to fall out, so their heads were shaved.All of these sound speculative, based on how a modern person would justify the action, but I've not seen a contemporary source re shaving one's head during an illness. Perhaps a reader here will know the answer.
In any case, this photo was later used in an attempt to identify the skulls after the children were murdered.
Photo via The Oddment Emporium.