What is a person in "pelvis cloth"?
What kind of clothing is that?
In what context is this expression used?
A pelvis cloth appears to be a more elaborate loincloth, the latter being, according to the OED,
A single piece of cloth wrapped round the hips, typically worn by men in some hot countries as their only garment.
You can see it in Eadweard Muybridge's famous movement sequence photographs, like this one.