It's not an aircraft I know that much about, but I think Wojtek is correct when referring to the last profile, and the orientation in general.
The black triangle marking is a continuation of the marking used on the fourth Staffel of Jagdgeschwadern, formed as a fighter-bomber Staffel within each Gruppe, and is therefore a 'standard' marking, just as the bars or welle were.
This marking was always placed aft of the fuselage cross on both sides, with the individual aircraft number (or letter, in this case) in front to of the cross, so it would make sense that this practice was continued in Panzer Schlact Gruppen, although, as can be seen from the photos, and as sometimes happened in the JG(Sch) Gruppen, there were exceptions.