Curious about this, from weight gain sub. 29M, 1.5 yrs, 142 lbs

1st 5 pics 142 lbs, last 3 pics 112 lbs. Says 1.5 years. That's 30 lbs or pure muscle in 18 months at age 29. Likely 36 lbs of pure muscle in 18 months as he's also leaner in the after pics. What do we think?