Idiotic adjectives thrown around by bodybuilding 'experts' all over the world:
'Granite-Like'
'Dense'
'Spilled Over'
'Muscle Maturity'
'Bloofy'
'Champion'
'Athlete'
To answer your question; it isn't. Can't see any striations? Surely it's the muscle itself! Not the skin and water encapsulating the muscle, but the density and maturity of the muscle. Yes.