The largest lot appearing section is already there, and is a separate parcel associated with some light industry. It looks like this proposal adds about 20 parking spots, which seems okay to me as these are to be commercial buildings. The abutting neighborhood is not really dense enough at the moment to provide all of the customer base, nor will Forest Hills passengers likely be enough for that purpose because it is mostly a transit point, rather than a destination.
These parcels are small, they will not on their own achieve enough commercial purpose to change the nature of the neighborhood, so they will need customers from further away, some of them arriving by car.
While I would like to see bigger, bolder, denser, as an incremental approach, this doesn't look bad. The buildings are attractive enough and comparable to other recent development in the area (Staples, Roslindale Health Center, Washington/Beach renovation). More importantly, they fill in a dead zone on lots that are arguably not ideal due to size and peculiarity of shape. To me it looks like a definite improvement to the neighborhood. Is it the very best that could happen? No, of course not, but it is a good first step.