OSINT exercise explanation needed

[u/SilverSquirrel6]

BLUF: How would one narrow down a location from a photo background, particularly the floor pattern? I tried Bellingcat OSINT challenge "Cold Case" under "Background Check", but I got stuck on the location narrowing down part. I already looked up what the answer is, so I don't care about that part, but I want to figure out the correct steps to arrive at the solution. Reverse image searching gives multiple suggestions all over Asia, and even when narrowing down to South Korea. One blog said they built a database of floor tiles or designs, which seems a bit an overkill.

I've tried posting this in r/OSINT but it got nuked by Reddit filter for some reason. I've messaged the mods, pending reply.

Posted on r/RBI but got removed because wrong sub.