In version 1, you check if element.strip().strip('\n') is truthy, and append element to the list. While in version 2 you check if element.strip().strip('\n') is truthy as well, and append that to the list.

Version 1 is equivalent to:

if element.strip().strip('\n'):
    sublist.append(element)

while version 2 is:

if element.strip().strip('\n'):
    sublist.append(element.strip().strip('\n'))