Clover has a trendy, eco-friendly vibe. All of the silverware, plates and cups are compostable. Orders are taken with an iPhone by one of the friendly attendants milling around the front of the cafe. The decor is somewhat futuristic, with white plastic cubes instead of traditional chairs. The food is reasonably-priced and perfectly adequate, if unremarkable.
My one gripe is that there are no non-dairy cheese or mayo options at Clover, so if you order the BLT or the BBQ Seitan Sandwich, you have to ask that they leave off these items. The lady who took my order spent several minutes trying to convince me that the BBQ Seitan would be terrible without cheese and mayo, and that I should really consider ordering the Chickpea Fritter (which is basically a falafel sandwich) instead.
I insisted upon getting the BBQ Seitan, and it really wasn't bad without the dairy fixings. I also ordered the Rosemary French Fries, which were pretty standard french fries with a few flecks of rosemary mixed in, and the Tarragon Lemonade, which was very unique and delicious.
Overall, I would say that Clover is a good option to have, especially if you're already in Harvard Square, but I wouldn't go out of my way to eat there.