Sorry, but I didn't mention the specificity of internship. But as you may already know, Psychiatry doesn't only include medical treatment but also psychological. So my interest being in only Psychology, I worked mostly on such cases and studied them where least medicines were involved and more of the talking and psychological tests. Being an Indian, I can say people here don't know much difference between Psychiatrist and Psychologists, but for both psychiatric or psychological problems, they go to Psychiatrist only. So lady luck was in my favor in the internship where I had the opportunity to learn cases including non medical treatments. That being said about my internship, I think my this internship should definitely catch an eye for the admission recruiters.
Also, I think I have compelling reasons as to why I want to change my career from Engineering to Psychology and I'm also clear with my vision. So that shouldn't be much of a problem (I guess). Because I know that anyone would want to know the reason for such career transition, and they can accept me only if my reason and vision is satisfactory.
Also, I wanted to ask, what is the scope of getting selected for PhD program after successfully completing a masters with an around 3.5 GPA? Will my undergraduate field affect my selection in the PhD program?