while和for修改列表的问题

需求：一家公司需要对打印过的设计进行移除

1.当使用while时

unprint_designs=["iphone case","robet pendant","dodecahedron"]
designs=[]
while unprint_designs:
    nsg=unprint_designs.pop()
    print("Print modle:", nsg)
    designs.append(nsg)
print(designs)
输出为

Print modle: dodecahedron
Print modle: robet pendant
Print modle: iphone case
['dodecahedron', 'robet pendant', 'iphone case']

2.当使用for时

unprint_designs=["iphone case","robet pendant","dodecahedron"]
designs=[]
for design in unprint_designs:
    nsg=unprint_designs.pop()
    designs.append(nsg)
print(designs)
输出为

['dodecahedron']
['dodecahedron', 'robet pendant']
['dodecahedron', 'robet pendant']

2中design没有用到，nsg接收了unprint_design的移除，到现在没有明白为什么会造成输出的缺失