I am far from a subject-matter expert, as I've largely done striking martial arts, and my current art (Capoeira) avoids prolonged grappling for style and tradition reasons (TL;DR, it's considered messy, doesn't tend to go with the music, and isn't terribly clever most of the time), but this page does a pretty decent job of breaking down the three major sprawl types I've seen used.
- Standard sprawl, legs out, on your toes, even weight - This is what almost everyone learns first as a defense against a double-leg, or a tackle scenario, legs shoot back, and you drop your weight on the attacker's torso to unbalance him. By staying on your toes, you maintain more mobility, but are slightly less stable.
- Square sprawl, legs out, hips down, even weight - This could be characterized as a deeper sprawl than the traditional standard one, with the legs and hips going down to the ground to further ground the opponent.
- Single leg sprawl, legs out, one hip dipped to the ground, uneven weight - contrary to the name, both legs still shoot out, but this is typically done as response to a single-leg takedown attempt, with the hip down corresponding to the leg that's been grabbed. Depending on how uneven you make the hips, this can be anything from looking a lot like a standard or square sprawl, to one leg crossing over the other.
To me, the first image shows square sprawls, although Ramsey currently has his hips lower, while the second one shows a single-leg sprawl.