Ok let me give you an example.
Case 1: Total daily vshares = 100M, a post's rshares = 1,000 then a post's vshares = 1,000^2 = 1M (1% of the total payout). If a person gives 100 rshares to the post, he will get 1M * 100/1000 = 100,000 vshares (0.1% of the total vshares)
Case 2: Total daily vshares = 10M, a post's rshares = 1,000 then a post's vshares = 1,000^2 = 1M (10% of the total payout). If a person gives 100 rshares to the post, he will get 1M * 100/1000 = 100,000 vshares (1% of the total vshares)