Contact pics not being displayed correctly

(Issue title)

Summary

(1) In the webinterface, contact pics are displayed only when clicking on the respective contact. (2) Furthermore, png pics are not displlayed correctly in the contact list

Both issues do not appear in my contact app on the phone.

Steps to reproduce

I just enter the webinterface in 'contacts'

What is the current behavior?

(What actually happens)

Relevant logs and/or screenshots

2 screenshots