This is a never lived in 1 year old town house. 200 amp Square D panel with copper conductors for the 110 circuits and aluminum for the 220. I have often seen conductors where they cut off strands to fit them under a screw or into a breaker and obviously you cannot reduce the diameter of the conductor so you call it out. I haven’t seen this before and I don’t know why the electrician would bother to do it. Any thoughts?
The conductor size needs to match the range of the lugs on the breaker. That looks like a Sq D Homeline CB. Probably has a range up to #10 or #8 AWG.
Call it out,as he has changed the #gauge wire.
Are you not suppose to call it out when you have aluminum branch wire; or at least recommened futher evaluation?
Not for 220. At least it’s OK here. Even solid alum. 220 is OK here.
Won’t some of the electrons just bear left, and the others bear right, at the fork in the wire? 
Al in TN
Only solid, and you won’t see that in new construction. That was done in the 70’s…
As for aluminum wire 10ga or smaller is no longer allowed per the nec. The do it selfer with the strands split it is not acceptable. The conductor is oversized for the breaker or the wrong type or the equipment is in ?. u can never cut or reroute strands to do anything.