Tyra uses her slave as human furniture with two functions, he is her seat and ashtray, two in one ;-)
She sits on his throat first in schoolgirlposition and smokes a cigarette and uses his mouth as ashtray, sitting on his throat, his head between her tighs gives her good control over her ashtray-furniture.
Later she streches her legs for more comfort... her comfort, not his, because with streched legs her full weight comes on his throat, breathing is more difficult, reaction is more gasping for air...
A gasping ashtray ;-)