well... animals develop these characteristics to help them survive. so its either for camouflage or display to attract mate. since it doesn't seem to be trying to camouflage with its bright golden and black stripes , i believe it is to attract mate. perhaps like some of you said,its about mood. or more like confidence in finding a mate. as in, a stable dat thinks he/she will find a mate. whereas an unstable one , perhaps he might be perfectly healthy physically, but deep down, his/her heart is hurting without love of a mate ._. dunno ^^;; thats my opinion, i'm not in animal psychology xD