Well, watched summer league and while he looks like he added a little bit of muscle he isn't as big as that picture suggest. Qi still has a very long way to go with his body development, but glad he is making progress!
i think that is photoshopped, this picture looks like the one that Yi had when he got really lean and buff a few years back.
Perhaps, I think it can be done as soon as 24 or 25 if he works hard though. When/If he does fill out, he can have a huge impact. Some guys just need 4-5 years to get their bodies right for the NBA, like Whiteside.
Also, Rockets legend Yao Ming spending some time with Qi at the beginning of the video embedded in this article: https://news.cgtn.com/news/3d3d674e7a55444d79457a6333566d54/share_p.html Some quotes from Qi: Can't hurt for Yao to be giving Qi some advice: Chairman Yao would have been a great nickname!! haha