A male (front) and female (back) frozen crest lizard.

The crest was definetly some form of display structure to attract males or similar. Such structures are also often used by animals to display to other members of their species how healthy they are, because any additional bodypart and vibrant colours need additional nutrition and if there's a lack of those, the body parts don't get that big or vibrant.

I covered my Cryos in primitive feather filaments. I don't know about the plausability of those i the case of this species but I saw some other paleoart on wich they were heavily feathered like this and I always like a bit fluff on my dinos.
They were also medium sized theropods and lived far south in antarctica and even though it might not have been as cold as it is there now, they sure needed some protection from occasional cold temperatures.