No you just have 3 down lineman with a RB in the backfield. Seen it used in high school a bunch. Been used in college on rare occasions. The inside receivers can't catch a pass on either side, but the outside 2 can.
You still only have 5 people to catch the ball, but you free up 2 additional "potential" blockers on the outside to clog it up and give our guys some chances to get into space with wide blockers.