Drop something new into a picture and have it look like it was always there. Describe the object and where it should sit, and the tool matches the perspective, light direction and shadows of your original shot.
How the add object to photo works
Upload the photo you want to change. In the instruction box, name the object and the exact spot, for example 'add a grey felt hat on the man on the left' or 'add a coffee cup on the table beside the laptop'. Mention scale and material if it matters. Run the tool and inspect the shadow and contact point where the object meets a surface. Refine the wording, then run again on the same upload until it sits properly.
Tips for the best results
Be specific about position, size and material rather than just naming the object. Say where the light is coming from if the scene is tricky. Objects that touch a surface look best when you ask for a contact shadow. Add one object per run and stack changes across several runs.