I do not think so. I like it if they are the same height, though.

It depends on the room's style. If very traditional, the answer might be "yes."

Any other style, I think you want objects, in general, to still be harmonious.

The same height, or same color shade, would accomplish this. The exact same lamp? Not necessarily. But, again, strive for harmony. If lamps are on two identical end tables on either side of a sofa, mis-matching might not look right…

I think the most important rule of decorating is having a room look unified and look "good."

There are lots of different ways to accomplish this… And, lots of ways to make mistakes. Always study your rooms and visualize (and try out stuff) before committing to any decision.

Happy Decorating!

Here are pictures of my end tables , looking to replace blue shade and lamp on round end table. Room is our main living area, not formal at all .

This little chart will help you get it right. The blue shade lamp is poorly proportioned for your space and furniture.