The drone impacted and penetrated the leading edge of one of the wings. The leading edge is thin for weight but its shape is what makes wings work, also a hole in the leading edge allows pressure to be applied to the inside of the wing which is not one of the directions it's designed to withstand.
It could have been worse, if the plane had a jet engine damage to the turbine in the front of the engine could have been catastrophic. The high speed carefully balanced spinning blades could tear the entire engine apart if damaged.