Krtartham prati nastam api anastam tad-anya-sadharanatvat (II.22).
Krtartham = (one) whose purpose has been fulfilled; Prati = for/to; Nastam = destroyed/non-existent;Api = although; Anastam = not destroyed/existent; Tad = (then) that; Anya = to others; Sadharanatvat = on account of being common.
Although it (the Seen, Prakrti) becomes non-existent for him (for Purusa, the Seer) whose purpose has been fulfilled, it continues to exist for others on account of being common to others.
In previous sutra (Tad-artha eva drsyasyatma = The Seen exists for him), we saw that this creation (Prakrti) is for the experience and liberation of Purusa. What happens to it (Prakrti) once the Purusa gets liberated? Above sutra tells us that it continues to be there for others (who have yet to get liberation).
Let us imagine, for understanding the above point, many persons are sleeping together in one room and having a dream which is common to all. Now, during the process of the dream, one of them wakes up. For him the dream ceases to be but for others it continues to be. Similarly the Seen (Prakrti) ceases to be for the Seer but continues to be for others.