According to the Alshich, Achashverosh sent his eunuchs to perform this task rather than officers to indicate his displeasure with Haman. It paralleled Vashti’s perception of being disrespected when she was summoned to appear before the king by use of eunuchs (Esther 1:10).
The Ginzei HaMelech uses this verse to show how humble Mordechai was, in that this giant of his generation still lowered himself to serve Esther like a servant. He writes further that this act was in direct defiance to Achashverosh’s earlier decree that men should be in charge of women (Esther 1:22).
Perhaps this use of language is what Tanna D’vei Eliyahu refers to when it writes that Esther spoke with Mordechai in a disrespectful manner.