Look, Tyki always assumes he's going to do something dumb with magic but Tyki indulges in him anyways because it is usually worth it. "Things, not people." He's been inside of Childermass' shadow. It was rather boring.

Not that he's putting any emphasis on the fact that Strange's magic was any less than his boss. It was likely far more grand than that. It's why when push came to shove he always told others that Strange was the better Magician. He watches with a quiet satisfaction as that potato crisp is pushed into his shoulder and his eyes narrow in scrutiny.

He's given permission to touch and Tyki does not hesitate. As he touches his shoulder, along the mirrored reflection, Strange will feel a tingle as his fingertips dip into his mirrored flesh. The general rule he gives to others is that if he can touch it, he can take it. He chooses to grab the potato chip, fingers ghosting along the bottom of it, and he pushes to lift it out of him. It's just, Strange's magic was always different and this realm always has estranged effects on his powers, "Hmm, interesting."