Exactly,trying to look tough and it ain’t working, At all.
They are mocking the pathetic bodybuilder poses. Calum is smart enough to make fun of bodybuilding, one of the reasons his vids are so popular
If he gained 40 lbs of muscle....Arnold gained 30 lbs on steroids, so whatever Calum is taking, it's strong stuff (Arnold was 187 cm in his prime, Calum is 188 cm, or 6 ft 2)