While that last thing you mentioned can be the case, to my knowledge, it’s mostly used to simply change up the mood—typically for comedic effect.
Also, I would assume that since it become somewhat common to do so, some authors would abuse it to get around drawing too many backgrounds. As an artist myself, I get it, but it IS rather distracting..
Sometimes the animal's expressions don't even match the vibe. I'm reading something rn where the character is sad and then there's some happy looking panting dogs in the back. Like, I wouldn't even think twice about them if they were sad dogs. It just feels off sometimes.
Though I get that they're on a weekly schedule most of the time, so saving time on not drawing a background makes sense.
Ok. This is usually something on my mind while reading, but what is the thought process behind random animal patterns in some panels of manhwa/manhua? Like the characters will be saying some stupid shit and there will be a random pattern of bunny men, llamas or dogs in the background.
Is it to avoid drawing an actual background and they just download the animals from some pack? Is there a cultural/language reason that's lost in translation (like for example maybe something they're saying is an animal pun that gets lost when translating to English)?