There is a space called “Memories” for personal comments or remarks about the profiled person.
Just my opinion, but I think profile comments (other than comments on the profile of an active member) should be genealogically relevant, a question about something stated as fact, information supporting or questioning a theory, noting what might be an error or conflation, offering an additional source, information for a proposed merge, and the like,
Since profiles can easily be changed, I also think comments on the perceived quality or appearance of a profile are more appropriately posted directly to the PM or contributor. If you think someone has done a super job on profile you can make an appreciation post here on G2G.