Not what you want to hear, but the mirror is too high. This impacts what is used on the buffet. The current lamps look too petite in scale up against the large mirror.

I'm sure it was a beast to hang but can it be lowered or replaced with one that is shorter or smaller? Google about the 2/3 rule which basically states that items should be 2/3 of the length of the item they are above and hung 2/3 above it. The rule is also used in many different areas in decorating to make things visually pleasing.

If the mirror stays, I think the one bulkier lamp works the best out of the two options. I like the gold lamps, but they do not fill the space.

Have the wire re-positioned on the mirror, so that it can hang in the vertical/portrait orientation. You can buy eye-hook and wire kits at HD or Amazon.

This is a good rule of thumb your dilemma

Arrange decorative objects, such as vases, candles, or books, in groups of three, varying their sizes, shapes, and textures to create visual interest

Lower the mirror to allow the lamps to be reflected . It will make them appear larger.