How to reproduce:
1. Create a new Unity project
2. In the Project window, right-click -> Create -> UI Toolkit -> UI Builder -> Open the created Asset
3. Add the Visual Element into the UI Builder's Hierarchy and select it
4. In the UI Builder's Inspector, go to Inlined Styles -> Variables
5. Observe the "+" and "-" buttons
Expected results: The icon size inside the button matches the Editor's standard
Actual results: The icons are too small
Reproducible with: 6000.6.0a2
Can't test with: 6000.0.71f1, 6000.3.12f1, 6000.4.2f1, 6000.5.0b2 (No variables)
Reproducible on: macOS Tahoe 26 (M1)
Not reproducible on: No other environment tested