I'm confused as to what the difference is..... Can someone clear this up for me please?

I know I have to send gifts, so would anyone like to receive cheap gifts so that I can get the achievement? :)

Are the Luminaire achievements even still working? I thought they get disabled after new years.

As for the difference, I don't think there really is one except holiday helper you have to send a lot more than just 1 to get the final achievement tier.

I think they are still working. I got Snowball and Mysterious Melody today.