Trim off the glass shelves and install the mirrored backsplash.

I was told that was not an option because tempered glass will shatter and is not made to be cut.

So then you have to go full bore get a mirror then new glass shelves??!! Or add some trim pieces to the face of the shelving unit to accommodate the added depth of the mirror/shelving. If you went with flat pieces they wouldn't really show.

Replace the shelves and do a mirrored backsplash.

Use metalic wallpaper or mirrored tile.

@njmomma, tile is also too thick. Do you know any good metallic wallpaper brands? I've been looking into some metallic peel and stick tiles that are very thin, but haven't had luck with wallpaper. TIA!

Mirrored wallpaper is extremely expensive. I have looked into it.

For the bar in our new home, I have wood shelves in my cabinets. I did not want to see dust on through the glass shelves. I placed 1/8" mirror sheets behind my upper shelves. Had it cut to cabinet size at Lowe's. I did not glue it in. The shelves hold the mirror in place. Did the same in a previous home and they held up beautifully. For safety, I warned the new owners, and even left a note inside the cabinets that the mirrors were not secured to the back. They can be removed easily, and without damage to the cabinet backs, if not wanted.

For the backsplash underneath, we used grass cloth.