A very important doubt in DP about Recurrence relations

This is the question. Can you please help me find the recurrence relation? If you will read the editorial you will find that they have used relation:
dp [ i ][ j ] = (the number of the gems on island i ) +
max( dp [ i + j - 1][ j - 1], dp [i + j ][ j ], dp [ i + j + 1][ j + 1]),
if i < m , j ≥ 2
but in recurrence relation we used to find out the previous state on (right hand side of the equation because that is how we solve sub-problems ) but here they have related dp[i][j] with the state that will be achieved afterwards that is dp[i+j+1][j+1], dp[i+j][j] and dp[i+j-1][j-1]. How are we solving sub-problems here? Can you please help me?

They array is traversed from the end