Wasn't Ba(OH)2 being added? So it'd be excess Ba2+ and OH- towards the end? HCl was already in the flask.like ideally you would talk about both, like defining why the conductometric titration occurs (due to moving mobile charges etc) and explain why it's the shape it is (like u have ions in solution at first making good conductivity, then reduces due to neutralisation of hydronium and hydroxide, then goes up due to excess h+ and cl-)