Weird theme issue -- not all control buttons display properly

[kdato]

Overview Description: I am on Enlightenment 0.26.99.xxx. Update: I have now tried celluloid on the very simple Motif WM and I am seeing the same issue. This suggests that it's an X11 issue (not seeing it on Wayland).

Steps to Reproduce:

1. the issue is always present

Actual Results: Previous Chapter, Rewind, Next Chapter, Shuffle Playlist, Toggle Playlist, Toggle Playlist -- the buttons do not display properly (although they are functional); what I see is a box with an ! inside.

Expected Results: All video control buttons should display properly

Version: celluloid-git; but earlier versions have the same issue

Additional Information: I attach a screenshot