Lego's official building instructions for The Sea Cow set include building instructions for building Emmet's couch from The Lego Movie. Are there differences between this model and the one actually featured in the movie? The one in this set looks different to me. Like, for example, this set has studs on some of the cushions to help minifigures stay seated, but in the movie the couch didn't have studs. Are there other differences as well? Any really major ones?
There are several discrepancies between the double-decker couch featured in The Sea Cow set and that depicted in the LEGO Movie. I've recreated the movie version as best I could in LDD and LDraw, and have compared it side-by-side with the Sea Cow set version. In the first picture, the Sea Cow set version is on the left, and the movie version is on the right, and vice-versa in the second picture. The notable differences are as follows:
As you pointed out, some of the seats in the Sea Cow version have studs on them so that minifigures will stay on better. Notice also that the Sea Cow version has one layer of blue plates, whereas the movie version has two layers.
The armrests are different. The parts that the two different armrests share have different color selections, and the Sea Cow counterparts are thicker and higher up than the movie counter parts. Also, the Sea Cow armrests contain the supports for the ladders, whereas the supports for the ladders are located elsewhere on the movie version.
The ladders in the Sea Cow version are higher up than the movie version.
There are round 1x1 studs placed on the bottom of the upper level of the movie version, but none are found on that of the Sea Cow version.
The back rests have more layers of plates in the Sea Cow set version than in the movie version.
The 1x2 plates with bars in the Sea Cow set version are used to connect the back rests with their corresponding seats, whereas in the movie version, they are not connected to anything. Because of this, the seats on the upper level are simply suspended in midair, and the back rests of the lower level are just sitting there with nothing attaching them to the seats. This is why replicating the movie version 100% and keeping it together is physically impossible. Why the makers of The LEGO Movie didn't simply attach plates with clips to those plates with bars they have there is beyond me.
In the Sea Cow set version, the two levels are connected by technic tubes which connect to 2x2 plates with holes. The two levels of the movie version are connected by long cylindrical 1x1 columns.