How long is your vanity top? Unless you're thinking of expanding your bathroom, you will probably want to stick to the same size you have now.

Adding a second sink is possible, but likely not cheap unless you can do your own plumbing. In most jurisdictions you would need to pull a permit. A lot depends on your current plumbing set-up.

Here is an idea that would save adding a second drain.

https://www.thebathoutlet.com/bathroom-sink-rectangular-white-ceramic-trough-undermount-sink-scarabeo-5137/product/45700

The bigger problem with a 2-vanity sink (besides no elbow room in that small space), is that you will lose so much precious storage space under the counter. We have a bathroom for the kids with 2 sinks, and I would gladly trade one of them for more drawers.

You really have no room for a second sink.

That doesn't look wide enough for a second sink unless you hate counter space. :-) Personally I would take counter space over a sink any day, but if this is the only bathroom in your house you may feel differently. You could center the sink and have a cabinet the full width of the space when remodeling. The current arrangement looks like a builder's least expensive solution.