There are a total of 26 illustrations which can be unlocked through various means.
Illustration
Conditions
Anemone Defending
After glow of year 19, choose the option to defend Anemone (min 80 creativity).
Anemone Grossed Out
Unlocked automatically after early quiet of year 14.
Pixie Bean Fever
Unlocked after late wet of year 13 if pixie beans are still on the menu and Tammy is alive.
Cal and Socks
Unlocked in geoponics (age must be 17+, Socks must be alive and Lum must still be leader). There is a somewhat easy animals check (around 30).
Cal Hiding Something
Unlocked in geoponics (age 15-16, Socks must be alive).
Saying Goodbye
Unlocked in year 16 after early pollen if the shimmer has not been cured (must go to say goodbye).
Dys' Transformation
Do not stop Dys from planting the bomb in year 18. During year 19, find him at the end of the Ridge and allow him to transform.
Music and Stars
Dys friendship 50 event (age 14+)
Faceless Attack
Automatically unlocked after glow of year 14.
Governor Marz
Talk to Marz after she becomes governor.
Nostalgic Marz
Marz friendship 90 event (age 17+).
Flulu's Sacrifice
Unlocked after late wet of year 14 if starving.
Nomi's First Game
Nomi-Nomi friendship 100 event (must support their art in the friendship 60 event).
Nomi's RPG Chara
Nomi-Nomi friendship 50 event.
Sexy Rex
Rex friendship 100 event (age 18+, must be dating or hooking up with him, choose "Let's get out of here. Together." in the event).
Cards with Rex
Rex friendship 10 event (Age 16-).
SFC Mystery Solved
Third in the series of "Secret Funtimes Club" events in command (age 11-13, do not choose "Sit this one out").
Sym Pounced Upon
Meet the "mysterious stranger" 3+ times or meet them at least once and have done at least 15 expeditions. Will appear under a yellow exclamation point event in any expedition that isn't Sneak Out. You will need to complete a perception check. This illustration will not appear if you call Symbiosis out by name, but that's a from a past life option, so if you have that then you've unlocked this illustration anyways...
Sym Falling
Sym friendship 80 event (age 16+).
Tammy and Echinacea
Unlocked in the living quarters after Tammy has had her baby.
Tammy Saved
Save Tammy (unlocked on a save reload or second playthrough.)
Tang on the Roof
Tangent friendship 80 event (age 17+).
Twins at the Bar
Work in the café 10+ times (age 18+, Dys must be in the colony). You need to complete Rex's bar sidequest to unlock working the café.
Attack on Tonin
Sneak out during wet season of year 11 and encounter the Manticore at the end.
