She gives an example. When she looks at the object in front of her, her mind can choose between two words, the English ‘desk’ and the German ‘Schreibtisch’ (Schmid is German). In an English context, her brain suppresses ‘Schreibtisch’ and selects ‘desk’, and vice versa. If this control mechanism is weak, the speaker may struggle to find the right word or keep slipping into their second language.