Do we have to take a shower if we see a dead person, or if we see the dead person in a picture or on a computer?

Praise be to Allah, the Lord of the Worlds; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.

What is reported in Shariah is that it is likable for the person who washed a dead person to make Ghusl after that, as it is likeable for the person, who helped to carry the dead, to make Wudu.

As for making Ghusl because of seeing a dead person, we do not know any evidence supporting that.

Allah knows best.