i would say sumo.
Hard to tell, but it looks like the weight is too light for speed pulls.
For the vast majority of people, conventional is faster than sumo. Just the mechanics of the two lifts. I imagine the same would hold true for you if you did your speed pulls at an optimal range. What’s your max deadlift?
I’d say your sumo was faster for those particular sets.
Your setup for conventional didn’t look as comfortable for you as your sumo setup, so that could be a reason for it being faster.
I agree with Rock–you should be using more weight for your speed pulls. When you get a little more weight on the bar flaws in your technique, even for speed work, will show up to a much greater degree. If you throw another 30-50 pounds on the bar, or more, who knows, maybe your conventional will be faster than your sumo. With a weight that’s such a low percentage of your max it’s somewhat trivial.