Interesting. I guess the dress took six to nine months to finish. It is implied that the season is passing by up until in autumn where the lady comes by for her clothes.
Maybe rather than time, the lady is the embodiment of winter based on page 6-7 still having tall grass outside the dressmaker's house and her spreading something, possibly snow, while she left.
Then again, I live in the tropics so I have little to no experience of the four seasons.
There's something captivating seeing static, 2D depictions of what is basically sewing, knitting, cutting, dressmaking tutorial that is not exactly dressmaking tutorial.