Seems like it is a an acquihire. I know somebody who said he gets a modest amount. Seems like they sold out too quickly? Series C or D would be better. But they just had A and sold out without a product?
In this case, it looks like they did a $50M Series A and a $240M Series B. IIRC, 5x is respectable, but I can imagine the VCs might be on multipliers here and eat away quite a bit of the common stock.
They probably got equivalent to staff engineer rsu refresher.