It doesn’t look like a seagull or a duck to me.
I think it’s Great A’Tuin, the star turtle, swimming through the cosmos. She’s even smiling. I don’t see the elephants on her back, though.
(If this post doesn’t make sense to you, you need to read more, specifically the “Discworld” series of books by Terry Pratchett. )
Read the Diskworld series anyway. They’re great fun. The “Seagull” looks more like a swallow to me, and the “duck” like a beetle that has been stepped on. Still, it’s not worth arguing with these astronomer types. Their eyesight is destroyed from peering through telescopes and trying to make out stereo star photographs.
“Seagull” has no taxonomic significance, there are no bird species called seagull. Many gull species don’t even live on a sea or near a sea, sealessgulls, lakegulls, riverinegulls, rapariangulls. Some gull species are so successful other species find them galling.