It's simply amazing how many different ways a cat can be drawn. The typical stance of Smilodon species is the same throughout despite the artist. Large stout cat body. Long saber teeth. Short bobbed tail like a bobcat, lynx, or a serval (though these are a bit longer than the other two). Usually snarling or lying in a group like lions. Sometimes spotted and other times with a lion's solid colored coat, rarely striped like a tiger despite the common name. Overall the general consensus on illustrating Smilodon seems to be already organized and, unlike dinosaurs, has been highly depictive (according to Webster's I'm making up words) of a high energy predator for many, many years.
The great paleo-artist Charles R. Knight painted a wonderful Smilodon years ago that looks a great deal like the Smilodon that modern artists still draw when they think of the big cat; an enormous flip is not seen here like it is for his paintings of dinosaurs which are thought of as extremely out of touch with the reality of dinosaurs. I would never belittle Charles Knight, one of my favorite posters ever when I was little was a copy of one of Knight's murals, but the truth is that he just didn't come up to snuff after the rethinking of dinosaur energetics and posturing twenty years after his death.
The skeleton of Smilodon is, itself, also very cat-like, which makes complete sense considering that Smilodon is, essentially, a giant prehistoric lion from the Americas. Regardless of this, however, it is very important to remember that the genus and the family which the three species of Smilodon belong to have no living relatives in our modern world. Smilodon, also, was not built like your tabby or even much like a lion which is capable of admirable speeds. Smilodon did not possess the leaping ability of the tabby nor the speed of cheetahs and maybe not even that of lions despite the similarity. The skeletal muscle attachment sights tell a significantly different story which leads us to the conclusion that Smilodon was, despite being a cat, built mush more like a Grizzly Bear. Muscles and strength would match a lifestyle of a heavyweight wrestler far more than a lithe featherweight pouncer when it comes to Smilodon.
The body of Smilodon here looks lithe and still powerful, but maybe almost too thin. The saber teeth we know, just from thoughts of our own teeth and looking at the thin recurved surface, that those teeth may not have been able to handle much pressure. Scientists have even gone so far as to prove that the teeth were not made for struggling with prey as large as the strength of the body was able to handle. The strength of the cat could tackle a bison, as an example, but it has been shown that the teeth would be liable to snap under the stress of puncturing a bison at full gallop which points to the importance of the cat's overall strength. Many conjectures have been made about the role of the teeth and we can examine those later, however. The jaw itself, though, has also been shown, through analysis of muscle attachment sites and modeling of the muscles, to be significantly weaker than would be expected. How does an animal like this kill things if its enormous teeth are likely to succumb to injury and it has a weak jaw?
Sometimes just being the strongest kid on the block goes a long way. It could be that the wrestling strength existed to tire out, knock down, subdue, and pin prey items so taht those teeth could work like daggers and cause the prey item to bleed out. An 1,100 pound cat wrestling a 2,000 pound prehistoric bison to the ground at a gallop seems highly improbable, but if these animals hunted as lionesses do, in a coordinated group, it could easily be done and a number of large strong cats holding the animal's head down for one swift stab of the jugular would certainly work. Todd Marshall's Smilodon is the only one I've shown here today that gives off that fierceness and power I believe. In a pose much like Knight's (it almost looks like an homage to me), this cat shows that it has the power and toughness to wrestle prey. I for one would actually be afraid of this cat whereas some of the rest look like pets, not that I'd mind having a Smilodon as a pet. Barney Rubble did afterall: