Thanks Ralf for pointing out this issue. I've created MDLSITE-7960 for it to be investigated and fixed.
Helen Foster ထံသို့ အကြောင်းပြန်ရာတွင်
Re: No user picture on the credits page [Resolved]
by Helen Foster -
Update: Thanks to our ICT support, Eduard, the problem is fixed and the pictures once again display fine on the credits page.