Hello, thank you for using Petco Pet Education Center, formerly Petcoach.
The incision, based on this one photo, looks normal to me for one day post-op. It is not uncommon for dogs to be lethargic a day after surgery. If she is wearing a cone collar, many dogs will not walk or move around much due to the cone. That being said, I do not recommend you take the cone off. Eventually they will figure out how to move around with the cone. If she is not wearing a cone, she should be.
Ultimately, you know her best. If she does not seem right to you then call your vet or take her to an urgent care vet.