I have seen mummies in the museum when I visited foreign countries. I remember I didn't feel comfortable. Now it is a contentious issue to display human body in museums. Some museums changed the term from mummy to mummified person when they talk about it. They seem to be wondering whether mummy is object or human. In many religions including Buddhism a body is thought as a vessel for the soul. Maybe that is why we cremate it. However, the way people treat dead body varies depending on their customs and religions.
Another problem of putting mummy on display is that most of them in Western museums are black, brown, and indigenous people. It is the legacy of the colonialism. Some criticize it as racism. They should be returned to their descendants to rest in their homelands. But in British museum mummy is an important element for visitors.