

It looks like some pieces are missing, where there are gaps in the white plastic but nothing seems to be installed there. Could the bigger round spot be for a second battery? At least that's what my mom said. I however doubt it because it looks different from the other battery spot, I already swapped that battery for a new one.
I'm completely inexperienced in this, I got this watch for 1€ but I think it'd gorgeous so I'd appreciate any input.