The Frenchman told L'Equipe that club coaches had been instructing him to tone down his emotions when he misses a goal-scoring opportunity.
"When I do this [putting his head in his hands] after a missed chance, the coaches get a bit annoyed.
"They want me to have a 'killer' attitude," Giroud said.
"Diego Costa shows no emotion. I am more emotional. I have therefore learned to control my emotions. I try to be less demonstrative."