According to the OED, there are multiple potential meanings for this term when this poem was written. It could have been a general term of address, especially for an older man or it could have been a way to refer to a master, governor, or foreman. This stanza itself does not make the distinction clear, but considering the focus in the third stanza on "men of fourscore" (line 23) it could be the first definition; however, a foreman or master would produce the image of control Winter has over the speaker.

https://www.oed.com/dictionary/gaffer_n?tab=meaning_and_use#3371962

The speaker is connecting another kind of joy to the snow through the image of boys having a snowball fight. She speaks to elderly men to bring back the memory of the good times they had in the snow. This brings the two age groups together.

The speaker is connecting another kind of joy to the snow through the image of boys having a snowball fight. She speaks to elderly men to bring back the memory of the good times they had in the snow. This brings the two groups of people together.

The speaker is connecting another kind of joy to the snow through the image of boys having a snowball fight. She speaks to elderly men to bring back the memory of the good times they had in the snow. This brings the two groups of people together.

"Eliza Cook, New Media Innovator" points out that part of the appeal of Cook's work is the fact that she focuses on everyday experiences and often invoked a cozy feeling for the readers. In this poem, she does not overtly focus on the challenges or politics surrounding England at the time. Instead, she creates a beautiful image of winter and a snowy day that any person could enjoy while subtly addressing Victorian norms.

https://wtamu-primo.hosted.exlibrisgroup.com/permalink/f/ahoafg/TN_cdi_walterdegruyter_books_10_1515_9781474475945_005

The speaker draws attention to the whiteness and purity of the snow here and line 8. In Christianity, particularly Isaiah 1 and Psalm 51, the whiteness of snow is a visual representation of the forgiveness a person can receive. The line "'Tis the fairest scene we can have below" (line 15, 31) most likely refers to heaven. The speaker draws the reader's attention to the biblical connections with the snow.

The word "marching is usually connected to military movement. This presents Winter as an organized and potentially dangerous force that the speaker enjoys seeing. This line may also explain why the first line characterizes Winter as brave. Most Victorians considered fighting and dying for ones country as brave.

This phrase as well as "delicate carpet so richly spread"(line 12) "glittering diadems crown'd" (line 14), and "ermine mantle" (line 30) invoke an image of natural riches that are available to everyone in the area instead of those who are very wealthy. While the speaker does not explicitely state it, the snow allows individuals who, otherwise, would not have access to material riches to have them in the snow.