Miksi 'right' on välttämätön?
Because tuossa implies the berry is right on a specific spot, not just generally there.
Yep, it's a "tuossa" versus "tuolla" distinction. "Tuossa" is more precise (right there) while "tuolla" tells you where someone/thing is approximately (over there).
I think that rhe prefixed 'there is' is not needed. First no finnish shown, second 'A berry is rigjt there' os correvt and perfectly good english