The sofa, pillows and art work extremely well together. Color, proportion and layout create an inviting look. The simple plant on the left also adds just the right touch.
The rug and coffee table almost seem to be part of another room. By having the rug and coffee table perpendicular to the sofa, the room feels awkward. The relatively simple appearance of the sofa and art are overpowered by the strong design on the rug and over-accessorized coffee table.
From a functional aspect, the coffee table would be uncomfortable to use for drinks because it is too far from the sofa and has a long slot facing in that direction.
Just a few changes would help this room look and work better. Against the concrete floor, a warm rug with more color would add personality. There are elements of blue and yellow in the artwork, and either or both of those colors would work well. The coffee table would be fine if it was turned so the long side paralleled the sofa and the pile of kaleidoscopes were contained or organized.
The lamp pulls the room together and its silver finish keeps it from being intrusive. It adds an element of retro style to the room, an always interesting touch. This room feels adventurous and interesting, so by making these simple adjustments, it would also feel well-designed.