Do not recommend.
I bought one of these years ago, and it was a nightmare. Not only was the canopy of the umbrellas not as tall as pictured, (I could barely duck under it) but if there was any breeze at all, it would swing the umbrella around. The mount did not hold well, and I spent an entire day as a nervous wreck.
I had gotten the umbrella for sun exposure, and the biggest take away was this: except at high noon, most of the day, sun *will* come in under the "sides" of the umbrella, unless you are driving away from the sun's position - and even then it will come under, it will just be at your back.
If you are getting it for rain, it will most likely be ineffective as well; as you are moving, the rain will come under the umbrella.
Depending on the vendor, some of the pictures are quite deceiving; increasingly on
Amazon, vendors are (poorly) trying to photoshop the item into stock photos. Usually the effect is noticeable, but there are some where they do a good enough job that it's passable.
The umbrella that I bought was significantly smaller than it was pictured, which just compounded all the problems I mentioned above. You will need an umbrella that is at least 4 feet wide across (if not wider) to shelter both the rider and the pusher.
Ponchos are *much* better for rain; sun hats and UV protectant clothing is *much* better for sun exposure. My friends here all know what they are talking about

it all comes from lived experience
If you have more questions, please let us know - maybe we can help you figure out an alternative solution!