Adobe's Generative Fill does not create, it only locates and substitutes close resembling images.
I.E. juxtaposing images below including a GF example manipulation of a clear glass addition.

PSC's Original Source Image

Kay Cee's Skillfully Crafted (under-voted) Contest Entry https://photoshopcontest.com/view-entry/223225/votes.html

Adobe's Generative Fill Clear Shot Glass Additions

Directly above, Gen Fill has substituted on file images that closely match one's request, but totally replace the original bottle and label in the selected area. Overall... pretty darn impressive, but nowhere near as impressive as Kay Cee's work above it. Not to placate nor advocate, just a simple fact.
Right now, translucency (such as underwater) is a challenge for GF. You can trick it by making the pixel selection less than 50% but that's a different condition and IMO hardly worth the effort.

I also tried gen fill and got similar crappy results. I believe Kay Cee's work was not gen fill, she uses a 3D program, probably Blender. The glasses are 3D and the program renders the image with the bottles in the background, that's how you get those beautiful glass distortions and lighting.

Yeah, I hadn't thought about a 3D program. I do believe Adobe's Gen Fill is much more capable and will phase in much stronger in the future. But at the moment I feel like Adobe scrambles labels and facial recognition to avoid legal complication.

That's true, and the images it uses are all from Adobe and copyright free, unlike the other AI image generators that take them from all over the internet.

Growing Pains
Class Action Lawsuit 16 min. info video. involving MidJourney, Inc., Stability. AI, and Deviantart

View youtube video

Saw video and others like it, …they got a lot of things to iron out.

hahah am a few months late to this post - i first used photoshop and path tool to sketch rough placement and shape of glasses then i import the sketch into 3dprogram blender 3d to draw over sketch and place the glass onto the picture, then use the picture for accurate reflections in 3d program. export a final pic into photoshop to tweak any awkward areas and make reflections on table -

Thanks for clearing that up KC, I used to use Maya 3D, so I'm familiar with the procedure.
Gen Fill can't come even close yet.