The way I see it, it's a completely optional thing for the game. New portraits that you can enjoy if you like. Or import your own. Perhaps you got the game on a sale and though "Man, that was a steal. Wish I knew it's that good, I would have payed full price." I admit presenting this content as DLC can be irritating to most gamers as we tend to have a completionist thing but still.
The reason for those four stars is that the game is too slow for my taste which is personal preference . The other thing I did not like about it was sometimes the level was obscured by things in the foreground. Other than that, it's a great game!
I actually quite enjoyed the game, but there is a problem that will never be fixed. Second stage of the game is really about food management and for select few players mama badger will not release food reliably. This mean that stage becomes really hard. If you are lucky and don't get that bug (to be honest very few people get it) the game is refreshing and enjoyable. I would totally give it 5 stars if it worked for me and didn't know people are having trouble.
I played this game for the first time a month or so ago and it still managed to surprise me pleasantly, even after hearing for years about how good it was. I deliberately avoided real spoilers though and if you have managed to do that so far as well, I strongly suggest playing it before something ruins that for you. I only have steam version so I can't comment how well does GOG version work.