Mobile startup Tiny Pictures secured a $7.2 million series B financing from Draper Fisher Jurvetson. Mohr Davidow Ventures, which led the A round, also participated. Previously, the company raised a total of $4 million, including seed investments from Reid Hoffman and Joi Ito.

Tiny Pictures operates the mobile photo-sharing service Radar, which lets members comment on each others camera-phone snapshots. Radar serves up 15 million mobile photos a month worldwide. Last November, the company introduced advertising in the form of public photo streams that movie studios and other companies try to get people to pay attention to. Blacked Eyed Peas singer will.i.am recently joined the company’s advisory board.