What does this image depict:
⇒ it depicts a white man washing his hands in a sink
What does the image show about the author's perspective on imperialism:
⇒ It shows that the author views imperialism as a positive thing because the white man's burden describe's European conquest as a way by which European powers impose their civilizations on other nations, in order to reeducate them and civilize them. This picture in particular says that other nations are dirty and dark and that it was the white man's job and duty to sacrifice himself to clean up those 'barbaric ' nations which is shown by the fact that the white man uses the soap to clean off the dirt of other nations.
Hope that helps!