The most common cause I see of glowing manifolds is excess fuel burning off in them thanks to low A/F ratios... the manifold acts like a thermal reactor from the old'en days.

If it has been running at high RPM for a while, it could do the same though regardless of A/F ratio. Hell, it could even be glowing from running too lean and pumping excessively high EGT's, but an engine like that, I doubt the tuner would have it running lean.

It's hard to take the picture out of context.

 

That's what I would think. Running lean = higher EGT's = glowing manifolds.