I think what they mean by small is how most interpret our defense, too: rely on movement and get upfield to disrupt rather than a head up, 3-4 type attack. Depending on the weight gains of Joe Jackson, Garvin and Bethel, our DL is "small" (though wingspan for days) in terms of prototype weight. Willis was 285 last time he played, but is now supposedly 300. If Joe Jackson really is up to 270 and Garvin up to 250, it doesn't really matter either way. They have to move their feet and disrupt. Shaq and MJ are the primary "prototypes" in the traditional "big" sense. Pinckney might play this year at a shade under 220. Jaquan isn't "big." Bandy isn't "big." Redwine has now gained weight, maybe the commentator didn't know that.
All in all, it makes no real difference because our style of play is to use explosiveness and disrupt. Happy about that.