This is a big topic but here, in one screen grab, sums up my take (pardon the pun) on it.
A newish company in the real estate listing photography business is offering two "enhancement services". 1. They will add a blue sky to a photo instead of the gray sky that was there the day the photos were taken. 2. They will turn the brown lawn green. They normally charge extra for these services but during this promotion they are free.
In my view, one of these is OK and the other isn't.
We don't always have the luxury of photographing a listing on the perfectly sunlit day. Adding a blue sky enhances the photo without changing the presentation of the property. On certain days there will be a beautiful blue sky above; on other days there won't. In any case the sky it's not part of the sale.
On the other hand, the brown lawn is going to be there until the season changes or new sod is installed. It's part of the sale. You could argue that the lawn will be green in the spring. Maybe or maybe not. And, the prospective buyer is going to see the brown lawn as soon as they arrive at the showing. What message does that send? What other edits or "enhancements" have been made in the marketing materials? What other important information about the property is the seller/listing agent trying to hide or misrepresent?