Your gallery wall pics are hung a little too high for the cabinet underneath. Either lower the pics or get a higher cabinet. As for the mirror -- hanging it depends on what is being reflected. Consider the scale of the mirror may also be too large for the cabinet.

Well, unless the mirror has a great reflection then no, if you do I might try vertical mount. Your console is low. Which is bringing the eye down.

The college frames are small and need just the right layout to work. When working with smaller frames less space between them appears easier on the eye. You can still have a fun layout, try adding a few 8x10 frames and frames of different thickness. Or hang them very square in a neat box formation. Also, complement the decor on the table to the pictures. And the pictures should come, or be much lower.

Can you touch up the paint on the lower part of the wall?

Try hanging the mirror vertically, which will provide needed height and connect it to the low buffet. You may be able to use the gallery photos in a different formation to the right or left of the mirror.

Can you get some silver legs for the buffet? If looks really low. Agree with feedback for art. You can incorporate some bigger frames with oversized matting and even white frames or a big of color in the prints. Do lower w/ middle of collection being about eye level. Add tapers in candlesticks and put to one side. Red ones not needed.

I prefer the mirror, hung vertically. Arrange the gallery in the master bedroom or hall.

If you decide on the gallery, it should shrink to 75% of the buffet's width. Placing the pictures one frame's width apart may do it, but you may have to change it to be more vertical if you want to keep all the pieces together. It also needs to start 5" above the buffet.