Repro steps:
1) Open the project
2) Create any new file in the Project window
3) Notice the blue arrow on folder(look at screenshots)
4) Open AssetImportIconDrawer.cs and comment lines 52 and 53(this will removed hardcoded offset to the custom icons)
5) Notice that the arrows are now drawn compared to Project View folders

Expected and actual behaviors in screenshots

Workaround: add offset to the drawn rects

Reproduced in: 5.4.0b7; 5.3.2p4; 5.2.3p3