Bad Icons for Hi-dpi under legend layout panel

[EmHain8]

running dev version

Describe the bug
icons are very small in the Legend Item properties gui in the Map Layout.

How to Reproduce

1. Use a Hi-dpi machine (Lenova Yoga)
2. Use QGIS 3.10 dev version
3. Open a layout window
4. Activate the Legend Item properties windown
5. Scroll down to the legend items display
6. Check out the icons under it

QGIS version
3.10.0-A Coruña
QGIS code revision
92102bd
Compiled against Qt
5.11.2
Running against Qt
5.11.2
Compiled against GDAL/OGR
3.1.0dev
Running against GDAL/OGR
3.1.0dev
Compiled against GEOS
3.8.0-CAPI-1.13.1
Running against GEOS
3.8.0-CAPI-1.13.1
Compiled against SQLite
3.29.0
Running against SQLite
3.29.0
PostgreSQL Client Version
11.5
SpatiaLite Version
4.3.0
QWT Version
6.1.3
QScintilla2 Version
2.10.8
Compiled against PROJ
7.0.0
Running against PROJ
Rel. 7.0.0, March 1st, 2020
OS Version
Windows 10 (10.0)
This copy of QGIS writes debugging output.
Active python plugins
DataPlotly;
smec;
processing

Additional context