I couldn't see the pic.. what did you purchase them as? When I first got mine they were rather small, slim... and seemed shy.. however as they have grown (now rather large) they are alot more bulshy and not shy about coming out during the day. I have never kept them in with peaceful fish simply because of the fact that most information you read about them clearly states to have them in with larger fast moving fish such as large species Barbs or Semi Aggressive to Aggressive Cichlids.
Alot of loaches are most active at night, so you might see them as shy during the day but you don't get to see what they get up to when the lights are out