Each slider controls how much a semantic concept influences the 2D layout.
Slide up to spread apart items related to that concept. Slide down to 0 to collapse that distinction entirely.
Try it: set "Paper vs Blog" to 0 and watch publications and blog posts intermix. Or crank "Structured Prediction" to 2 and see those papers fan out.
Advanced reveals PCA residual dimensions (semantic structure not captured by named themes) and lets you switch between embedding models.