Personnally, I like the chairs and sofa but since you can't replace them, soften them up with maybe a throw and some pillows you really like in great pattern and colors.
Decorate around them with the things that make you want to come home. Maybe a new rug for underneath the 'new' coffee table since I believe you will be storing this one which I agree..too bulky. Maybe put up a 'gallery' wall of your favorite art or family photos but I would suggest using the same frame color to keep it cohesive. Humm...that's about all I can think of but I'm sure my fellow ATers will have more and even better suggestions. Good luck.

I think LYONSTILL is right on target. The room looks very sterile to me. You need color and softness: rugs, pillows, throws, oh, and your own artwork. After you remove the light fixture and add a new, smaller coffee table, I think you will have a great room!

How long will you be in this rental? My suggestions would be different if it's only a few months vs. a year.

But first, inject some of your own personality into the space. Things that you like. Some artwork on the walls, a throw, some pillows, books, interesting objects that you find on walks, etc. A live plant or two can really warm up a room. Get a bookcase and fill it with books that you love. Put up some photos of your old city, or home or state. Or a big world map. Add in some pictures of people you miss.

For replacing the carpet, tables, etc., ask around about local markets, second-hand stores, etc. Exploring these will give you a chance to learn about your new city, and also to find some bargains with which to decorate your home. Get some cheap fabric and make curtains.

Hang nice paintings or pictures on the wall, failing that paint walls.

Get a nice big rug with color, pattern. I suggest a more organic or artistic motif to relieve the blah-ness of the furniture. Maybe something of local weaving to drape over the ugly coffee table or put behind the couch. Take it all with you when you leave, since fabric folds up easily.

I'll agree with everyone else. Throw blankets, fun, big pillows, artwork. The furniture is at least fairly neutral and can be worked with. That looks like a great window so why not dress it up with some funky curtains or some other treatment? How about a rug? I don't like the coffee table so much, maybe you can put a small cloth there, or put books and things to clutter it a little? I'm assuming you can't DIY the coffee table it if its a rental!

I had a similar problem while living in a furnished rental in Singapore for a year. I decided to liven-up the neutral palette with pops of bright orange and red using cheap accent pieces all over like a trash bin next to the desk, bright pots with houseplants and bright pencil cups or coasters. A little color and greenery goes a long way! I also tried to combine my nesting in Singapore with souvenir shopping, and bought ethnic textiles that I folded neatly to temporarily cover chairs or open freestanding shelving (ok, I used a stapler sometimes, but it looked good!). Even placemats or plastic trays that are unique and special can do double duty as coffee table decoration and then are compact keepsakes in your suitcase home. Try buying a few of each inexpensive piece- I used matching Indian "placemats" (they were more like small plastic trays) on the cofffee table to hold remotes and by the front door for keys and change. You should feel free to experiment because if you decide that that throw blanket is not your favorite, certainly a friend or family member will appreciate it as a gift when you are back home. I am sure that in Chile there are amazing handcrafted baskets and textiles in addition to pottery pieces that you could find to create your own Santiago paradise!
Also don't forget that a big bowl of fresh local fruit does wonders, is inexpensive and edible too!!
PS I love the chairs to the right in the photo, actually.