Yes, Because the part of the sentence "Although it is pretty" won't be able to function on it's own as a proper sentence. However the sentence "winter isn't as pretty as fall", Is a independent clause at the end of the sentence. Hope I helped, Look at the images, It will help! :D
"The Gift of the Magi" remains a popular story for its sentimental narrative, with moral lessons around Christmas time. With timeless themes of youth, love, relationships, money struggles and Christmas it remains universally popular.