Probably an Albatros D.V or D.Va, because of its oval fuselage shape (as opposed to the D.III's more flat-sided profile).

Here's another webshot of an SE5a and the Albatros, and this one showing combat between an SE of No. 56 Squadron, again with von Hippel's "Blitz" from the "Green Tails" (Jasta 5).

Sorry it's small: