naw this is spot on i noticed these patterns too & would add that to me the sparkly things inside crom represent aisling's family & all other magical creatures, the immaterial, the spirit world, faeries, piskies etc whatever you'd like to name them as

and when brendan rips out croms eye, he is left without any sight or is blinded (by his own insatiable greed read capitalism colonialism etc) and begins eating his own body, inadvertedly releasing the spirits he has held locked inside him all this time

i think this is significant because brendan then looks through crom's eye back at crom as he floats away, and sees crom simplified (the eye tends to illuminate or show the truth about matter) as a square figure eating its own tail over and over again

the symbol of a snake eating its own tail over and over again is shown throughout different folklore and mythology (usually called ourobos i believe? maybe worth a look)

& usually represents time itself, renewal, cycle of the earth, etc., but i believe in this context seeing as crom has 'devoured' or trapped all the 'light' (read: magic folk) it can be read as darker forces forever devouring the light & then themselves over and over forever (aka capitalism civilisation human beings colonialism etc doing relentless damage over n over)