Why does that sound odd to Tamaki? Maybe his only exposure to magic has been through the fae, or backwards old men like Strange and Childermass...

"Like... devices used to generate barriers large enough to protect a whole city from monsters." That shouldn't be too hard to picture. Although... he might not need to rely on his imagination too much, as there happens to be another example right in front of his face. "My necklace is a sort of magic technology, too."

She refers to the red-jeweled gold choker on her neck. Since she never takes it off, Rita naturally has it here at the ball.