As long as the user and the target can both see each other and look each other in the eye for it to work. If IBT's user can make out the physical appearance of the target the ability would work. In the case of Achtung Baby, if the user was covered in makeup or some way the user could see or make out the face, the ability could work. As in the case of a stand like Enter Sandman, both IBT's user and Enter Sandman's users would need to make eye contact, not the user and the stand.
Something I didn't mention in the description, it would need to be bare eye contact. If the target is wearing something to cover their eyes, such as glasses (with lenses of course), or was behind a solid object, the ability would not activate.