Looks like they took a couple of normal, everyday ficus trees...
...and OD'd them on Miracle Grow.

It'd help to know the sun exposure Liz gets in her windows.

I use potted dracaena marginatas (aka "red-edge marginata" aka "madagascar dragon tree" aka "dragon tongue"), a potted money tree, and hanging spider plants for this effect. The dracaenas are about five feet tall now. They will grow taller if I let them. The money plant is also about the same height. Because my windows are facing East, I let the plants enjoy the sun but only through a sheer white curtain until the sun goes overhead (then I just pull the curtain to the side and let the trees enjoy the indirect glow). These plants must not bask in the sun directly because they will scorch. But they'll do well in any other type of sunlight as long as it isn't a direct hit. These trees are hardy. The only trick is to let the soil dry out just a tad between waterings but no more. Because the stems/trunks are tall and thin, you may have to suspend them upright by wrapping one end of string to the trunk and the other to a hook in the nearby wall. And turn them around once the foliage starts to lean toward the sun.

I don't have photos up online but I may soon now that you've inspired the idea. Good luck!

Plants will block the view form the street during the day really well, but come night you will have light on indoors and the plant's foliage will not really block much of the view the way blinds would do it, right?

I think the first picture is of finicky ficus. In the second photo the plant in the middle is a money tree.

One whole side of my apt is glass (floor to ceiling windows and sliding doors) and faces a golf course. I just took down all the verticle blinds in the livingroom/dining area. In one window are 2 Ikea metal book shelves that fit perfectly into the window frame. I keep my thrift store glass vases, snow globes and plant cuttings on the shelves. It doesn't block the light (plenty of that in Florida) and in the morning the sun shines through all the glass and the room sparkles. I was a little uncomfortable at first at night but now I'm used to seeing the darkness outside the windows. I keep the cat litter on the patio and it's outside the dining area. I'm think I'll put a wicker screen there so you can't see the litter but the light will still come in.

I'm redoing my apt and more then getting ideas from apartment therapy, I get the courage to try something different. Needless to say, I'm addicted to your blog.

Yes, that in the first photo is ficus benjamina (weeping fig) and that in the middle photo is a money tree. (A rubber tree would work well, too, though.) The ficus will want to drop its leaves if it moves a lot, but if the light is right for it, it will adjust once it's put there.

And yeah, for the best suggestions, we need to know about your light and your location - a south window in Chicago is way less intense than a south in Tampa. Also take into account any structures that shade your windows from the outside.

In general - large specimens are easier to neglect than the small ones of the same kind - less watering is needed.

Pothos or philodendron will thrive in just about any window, bright or not. You can grow them as hanging plants or on poles wrapped with sphagnum moss (the latter will grow bigger leaves.) They are very easy to grow. They usually grow as single long vines, so when one gets too long, cut off the tip and root it in water, and start a new one to thicken your window cover. Mature plants will sometimes backbud (ie. grow more than one vine from the root).

Tradescantia, or wandering Jew, will do well in a brighter exposure (east/west/south.) There are different kinds - some have solid purple leaves, others are striped with purple, pink, green, and/or white. They're also very easy to grow but they will get long and leggy, so you need to pinch off the tips (about 4" pieces.) These pieces, too, can be rooted in water; just remove all but the top two leaves.

Although a north window has the indirect light preferred by many house plants, it may be tricky to get the thick leaf cover you want for privacy. Your best bet is probably the pothos or philo. You could also try a large peace lily.

Verasue - it depends on the plant. I don't think you'll be able to see much through that ficus on top.

JaneyK, your room sounds awesome.

I live in LA too and I’ve managed to do this with smaller potted plants by building a 3-tier plant stand that fits the size of my window, about 5’x 3’. Be sure you pick out plants that will handle the available light well. My window is on the south facing side and gets full sun for about half the day, so I have mainly succulents, azaleas, fig trees, and full sun herbs. I actually seared a philodendron by leaving it there for an afternoon, but I’ve found that the plants do a MUCH better job at reducing the heat than curtains. If you just want to use one plant they have larger trees at OSH or Home Depot. You will also want to learn how to prune it to shape it to the size of the window.

Best of luck!