To reproduce:
1. Create a project in Unity
2. In Hierarchy window, create two cubes and parent one to another
3. Drag the cubes to Project window making it a prefab
4. Drag the prefab from Project window to Scene view
5. Drag the recent cube from Hierarchy view back to Project window making another prefab
6. In Project window, select the cube prefab and expand it

Expected: cube expanded, child cube's icon graphics is visible
Actual: cube expanded, child cube's icon graphics is not shown (check .gif attached), only appears for a brief second

Reproduced in: 2017.2.0a1, 2017.2.0b3
Not reproduced in: 5.4.5p4, 5.5.4p2, 5.6.2p3, 2017.1.0f3
Regression starts in: 2017.2.0a1

Note: graphics is also not shown for other geometry, sprites etc.
Note: restarting project doesn't fix the issue