A sentence refers to the pair of words which is complete in itself. In other words, a sentence contains a subject and a predicate or it may contain a main clause and one or more subordinate clauses to convey a command, exclamation, question or statement.
In the following statements, the sentences have subject and predicate,
B. The ferret has a silly look on its face.
'The ferret'- subject
'has a silly look on its face'- predicate
C. I really do like spinach.
'I' - subject
'really do like spinach'- predicate
D. The men’s bathroom is out of order.
'The men’s bathroom'- subject
'is out of order'- predicate
Hence, the sentence 'Winding up the pole' doesn't have a subject that's why it is not a sentence.