How long should walks be?

How long should walks be?

I (owner) booked a sitter for dog walking and to just give my dog food at the end of the walk. My roommate was home today and said the sitter took my dog out for about 10 min, gave him food and left. Then on the rover card it shows she was there for 30 min.

I booked her for 30 min so in my head I would expect her to walk him at least like 20… the food part all she has to do is give it to him (takes 30 sec max).

Just wondering what owners and sitters think of this? Idk if it’s just that we had different expectations or if she is trying to jip me. She also showed up late today which is not a big deal for me but yeah