Most resources I’ve found online say that “tonari” should only be used when referring to objects of the same category.
E.g. Tonari no Totoro (comparing neighbours), or you can say the bijutsukan is tonari the yuubinkyoku because these are both buildings.
And if you want to compare different categories of objects (e.g. people and condiments), you’d need to use “yoko”.
But the first example sentence in Bunpro’s entry on tonari is “Please grab the condiments next to you for me.” which seems to relate to the proximity of the person and the condiments.
Basically, I answered “yoko” in my review and I was marked wrong, but I delved deeper into the differences and now I don’t know what to think!
Any advice?