oh wow where did you find the bday art? I tried looking around and couldn't find anything.
i can't tell for sure since i don't know what the art looks like but maybe its a reference to Biyiniao. Its a mythological bird from Chinese/Korean culture that has only one wing.
"There is a bird here which looks like a duck but it only has one wing and one eye. It can only fly if it and another bird of its kind join together."
Much of Seungmin's motive's are still a mystery but Jaeyoung has been able find happiness through "joining together" with Seungmin. In a way the two are happy together lol in a way that they weren't able to by themselvs, kinda like how the bird can't fly until it finds its pair.
its on the latest unofficial chp33 dindin translation at the end or u can see it on author's twitter!!
heres author posted for print:
https://x.com/i/status/2084586431465558040

a piece of tape sticking the newspaper to the window in chpt 33 unsticking and letting a ray of light into the basement was such a good detail, im screaming, it coincides with Jaeyoung dreaming about Seungmin for the first time after only having bad dreams for years. they're so domestic together and i just can't get enough of the casual affection. The ray of light showing how Seungmin is making his way into Jaeyoung's heart and how light no longer needs to be a source of fear but one of hope
not to mention all the stuff with icarus, light/sun, and downfall. the scene with the wings and the photoshoot make me so nervous, its such obvious foreshadowing that i can't help but worry. But in that same line of logic manager Han telling them to tone down on the lighting(sun) shows that there are ppl who care and will protect Jaeyoung(icarus) so that he won't come crashing down this time