If I see a seriously skinny guy obviously doing SL 5x5 or SSLP, and they’re doing overhead presses (and only then - since it’s stereotypical and fraught to offer advice on any other of the lifts in those programs; also because mine is categorically decent with a PR of 205@ 182lbs bw), I’ll give them some tips if it looks like I could tell them something that would make it obviously easier to them or bring the pressure off their elbow or shoulder joints. But I’ll always ask about their program first and only approach if I’m feeling nice.