Tempest and Grubber is tasked to buy some things from the Ponyville Market. Well, rather tasked, she asked them if they could get some stuff. Tempest is the one who take it as an importent task and Grubber just likes to humor her.
Tempest wants to make sure the food is up to a princess’ standard (plus that it’s potentially not poisened).

Like to explore the idea, that Tempest has to relearn to trust ponies. In fact when she returned to Ponyville and became Twilight bodyguard/captain of her guards, to only pony she fully trusted was Twilight.

Plus how super serious with her duties she is, because she wants to repay Twilight.

Also stuff like how she stands out among the citizens of Ponyville, so it even takes time even for the locals to accept her (so is Grubber but that besides the point).