Hi 4550_s1020
Welcome to the Apple (user-to-user) Community.
Thank you for sharing what you want to do.
Wondering if that is possible on an iPhone. Taking a look at the possibilities below.
Maybe this is the new feature you are trying ... seems it works with text ?
Copy and translate text from photos on your iPhone or iPad - Apple Support
and
Use Live Text to interact with content in a photo or video on iPhone – Apple Support
Else:
Maybe this the feature you are using:
Lift a subject from the photo background on iPhone – Apple Support
- says " Tap Copy, then paste the subject into an email, text message, or note.
Tap Share, then choose a sharing option, such as AirDrop, Messages, or Mail."
Doesn't offer pasting it into another picture.
Else:
Cut, copy, and paste between iPhone and other devices – Apple Support
Can copy images to the clipboard, so they can be pasted elsewhere.
Editing has possibilities, but doesn't seem to do just what you want to do.
Edit photos and videos on iPhone – Apple Support
Sorry I do not know just how to achieve what you want on iPhone.
Seems like "professional" software like Photoshop would work!
Hope something here is helpful.
All the best :-)