When Catherine borrows the wooden cross from Potemkin, it is hanging from a simple string. But when she gives it back, it has been strung with matching wooden beads. There is no explanation if this is a different prop or if Catherine added the beads herself.
When Catherine trades in her virginity to get pregnant, the skin of her mate's back and legs is tanned, while his buttocks are perfectly white. There were neither sunbathing nor a pair of trunks in 18th century.