By realism, I assume you mean something that looks "natural" for a human.
For your purpose, lets exclude physiques that are extremely atypical for medical reasons. Genetic or hormonal abnormalities can produce unusually short or tall stature that is also atypically proportioned.
Also, recognize that what you're referring to as "large frame" has a complex relationship with height. People tend to associate "big" with tall. A surprising number of "bad-ass" Hollywood action stars who look big on-screen, are actually short, and camera tricks are used to make them look big relative to the other actors.
Large and small frame is somewhat of a misnomer. Skeletons are shorter or taller, but otherwise surprisingly similar. The bones can get thicker and stronger if they are asked to support more weight or anchor more strenuous muscle activity, but that doesn't contribute much to the physique. What you see as the physique is primarily the muscle and fat. Take some stereotypical examples:
- Skinny teenage computer geek, no athletics: Minimal muscle development, and little body fat because a high metabolism and rapidly growing body burn off calories. Dwayne Johnson in your picture here was always "big", but take Arnold Schwarzenneger, pictured in Elmy's answer to your previous question. Here's what he looked like as a school-aged kid:
Source
Someone with significant obesity but still active: They are carrying a lot of extra weight in the form of body fat and excess skin. So everything they do builds muscle (although their heart and lungs might not have the capacity to support endurance for athletic activity). Some of the body fat will be distributed all over, and some may collect in specific areas. If most of the fat is well-distributed and the skin is still very elastic, the person can look "big" but not unnaturally proportioned. That was sometimes referred to euphemistically as "large framed".
Construction worker or lumberjack: They are likely to have well developed muscles everywhere and some well-distributed body fat. They may look big but fit.
Athlete: They will have well-developed muscles. If they focus on a single sport, specific muscles may become especially developed. Depending on the sport, they may have limited body fat because they burn off calories and avoid excess weight.
Body builder: They have extremely over-developed muscles (even if they don't use steroids to make them artificially even bigger). To make the muscles more visible, they purposely get rid of almost all body fat. Body builders competing for the big titles will try to over-develop muscles everywhere, so at least it's uniform (like that picture of Arnold in Elmy's answer, reposted below for reference).
Source
That doesn't look natural in the sense that a human would normally look like that without serious intervention, but it also doesn't look like a different species. Many people find it at least interesting and not unpleasant to look at. Using steroids to grow ridiculous-sized muscles in specific places while other areas are normal size stands out as strange, like the "unnatural" pictures in your previous question.
Here are pictures of the same person before and after some physical development:
Source
The after picture looks like the person is wider and has a larger frame. The difference is primarily muscle.
Image source unidentifiable
