I'm familiar with SG's work and marketing approach. There have been comments by male observers of her practice in the past that have queried why her patients don't do the less invasive form of "masculinising" their forms by simply starting to lift weights.
It would certainly be a cheaper solution, and the tactic most young males would take if they wanted to be perceived as "more manly".
From this came the conclusion that this is not about presenting as more, or thinking like a, male per se, but rather a complex internal desire to express the patient's will against a body they feel they cannot control, and that these patients felt they would rather be read as overweight males than overweight females.
This oddity is certainly also a feature with many lithe transboys/men, who seems to want to appear as very slim teen males who are barely pubescent. In reality, many teen males of that body type tend to have a hang up about their "skinniness" and lack of muscle and strength.
In short, these transmen are not portraying a typically male response to their body image, which further underlines the fact they are not particularly thinking in a socialised masculine manner.