Hello AngrySprite - From your screenshot, looks like you have "Lighting Quality" set to "Low". I just tested this, and setting to "Low" makes it look just like your screenshot. Screenshots on Gateway and New Posts should always be using "High", that's why you would see a difference there. Hope this helps!
Excellent feedback guys. We are in the middle of making an overhaul to the Warlock movement animations and sprint animations/FX. Look for them in an upcoming preview patch!
This thread was brought to my attention... I'm getting it fixed ASAP so it can go into a patch soon. Thanks for your patience, and for pointing this out!