Hey yo I’m sure someone has mentioned this already, but I’ve only seen people vaguely saying “lily”, so: it’s a pink impala lily specifically. Y’know, just in case you wanted to know.
Thank you! With that information, I was able to look up possible meanings.
Lilies represent virtue friendship and devotion, and are used in funerals to symbolise the spirits of the dead regaining their innocence. They are also the birth flower for those born in May. (Source: Teleflora.com)
Pink symbolises self-love and love for others, friendship, tenderness and inner peace. It’s the “sweet side” of the colour red. (Source: Bourn Creative)
My best guess? The flower is Wilford.
More specifically, it’s Damien and Celine’s feelings for Wilford. It’s Damien’s friendship that refuses to die, and Celine’s romantic love which she released him from some time ago. Damien marveled that his fondness for Will is still vibrant and warm despite all else around him being dead and cold, refusing to “die” in the face of everything that happened. Meanwhile Celine is cynical about ever being with Will again, hence why she claims it’s “probably already dead”.
It’s the one thing that reminds them of their humanity. Their mutual affection for the Colonel.