id is a “pointer” to tensor itself, which is compound object containing other objects, not the data
I think this is similar to (soft / shallow) copy()
>>> a = [1,2,3]
>>> b = a.copy()
>>> a is b
False

as you can see a and b are different objects, but
>>> hex(id(a))
'0x7fb56080a180'
>>> hex(id(b))
'0x7fb560817740'
>>> hex(id(a[0]))
'0x7fb64fa72930'
>>> hex(id(b[0]))
'0x7fb64fa72930'

they both point to same elements inside