The Description from the original imageset. Strange that it does not seem to have been posted already.

Heya!

If you are interested in seeing more art or future projects
from the artists in this special Valentinespone folio,
here are some links to their personal websites.

Lizombie
http://its-lizombie.deviantart.com/
http://lizombie.co.vu/

Pwny³
www.pwnypony.com
http://www.furaffinity.net/user/hallogreen

OneObese
http://www.furaffinity.net/user/oneobese

CyanCapsule
http://www.furaffinity.net/user/cyancapsule
http://cyancapsule.tumblr.com/

Siden
http://besidenmyart.tumblr.com/

Atryl
http://atryl.deviantart.com/
www.atryl.tumblr.com

Tyelle
www.furaffinity.net/user/tyelle/
www.http://thehorsesays.tumblr.com/
www.weasyl.com/profile/tyelle

Kevinsano
www.furaffinity.net/user/kevinsano/
www.ponymouthhugs.com/
http://kevinsanoposts.tumblr.com/

Fr0styRyan
www.fr0styryan.deviantart.com
http://www.furaffinity.net/user/fr0styryan/
www.fr0styryan.tumblr.com

Group "staight" -> https://e-hentai.org/g/1113445/cd46c463e5/

THIS GALLERY DOES NOT BELONG TO THAT GROUP.

Also, LITERALLY FIRST PICTURE OF THIS GALLERY IS A YURI THREESOME. WHAT. THE. FUCK. HOW BRAINDEAD ONE NEEDS TO BE TO USE THAT TAG.
I even won't touch all the "this tag went not where I was expecting it to go. maybe I did something wrong", for that line of thinking demands ability to THINK. Which far more that could be said about the protozoa that slapped "straight" on this gallery.

=====

To answer you question, OP:
1) Most of this artpack was posted in different galleries previously; too many dupes.
2) No one bothered enough.

=====

EDIT: one picture is still missing - NSFW version of Sombra/Chrysalis promised here https://e-hentai.org/s/ff354bdcb7/2254071-32

Full version (SFW+NSFW) in the torrent.

Base +31, Sol37 -6, fjsdhgft7vg +7, psycobeard -7

Plus the order's not that logical. Ideally, the list of artists would be at the start or end, and each SFW one should be before its corresponding NSFW one.

Base +6, dragolem +27