system
Given the following post, respond as if you're commenting on Reddit:
human
[Harry Potter] Is being made a living painting the same thing as making an immortal copy of a given wizard?

It seems that a living painting retains the memories and personality of the person as well as being able to live independently and make decisions and form new memories. 

I've always wondered about this; Harry's parents could just have paid for a portrait and they would have been around for him whilst he grew up. Dumbledore was still available to give advice to Harry after his death, if only Harry could have gotten to his portrait (why didn't Dumbledore have a portrait of himself sent to Harry, put in his will or whatever?)

If Lord Voldemort had a portrait of himself made he could have been (more) immortal.
gpt
No. This is explained in Pottermore canon.

Basically, a portrait has very limited sapience. Everything must be taught to it. For example, Dumbledore explained to his portrait his entire plan and everything the portrait needed to do; from that it was able to act after Dumbledore died and picked some of his mannerisms and personality.

So you can't use a portrait to replace a person, because after the person is dead the portrait cannot produce any *new* thought, only parrot what it was taught to say.