Marie Antoinette was less than impressed with Madame du Barry when she learned that not only was her position at court bought, but her appointment was made to become the king's favorite.
While this was all very well for Louis XV the young archduchess, now dauphine, was repelled. Her new aunts (Louis XV's daughters) encouraged the catty talk and gossiped over Du Barry with Antoinette. Creating alliances, and upholding her virtues, she felt she was not in the wrong for ignoring the woman.
Her mother and the Comte de Mercy both held a more worldly view on the situation at Versailles, and Maria Theresa did not hesitate to address the situation. Mercy, who acted between the two, tried to explain this bigger picture letting the young girl know that "if the alliance, her mother's life-work, were now to be broken, the blame would lie at her door."
After these concerned discussions, Marie Antoinette knew she needed to make this extension of peace, if you will, and agreed to acknowledge Du Barry in public. She would not compromise her virtues but understood she had responsibilities as dauphine. The plan for this exciting moment was very well correographed, as was everything at Versailles!
Set scene! After the card party, Mercy was able to pull Du Barry aside, and Antoinette began going around the room. Apparently her conversations with some guest were a bit extended, and this could have been due to anxiety. But she genuinely wanted to speak to this lady and fulfill her duty to the king.
Right before she reached the two, her husband's aunt, Madame Adelaide hurriedly walked up to her, and in a very straightforward abrupt way told the dauphine that they (her and Adelaide) must go await for the king in Victoire's room (Adelaide's sister). The instructions were so sudden, and from Adelaide - the king's oldest daughter - that she practically blanked and agreed to be hurried off. Unfortunately she was so close to reaching Du Barry, it was viewed as her purposefully slighting her, making things more uncomfortable than before!