It has an extra overflow tile "..." at the end which follows the stacking behaviour. Due to the styling of compound-web the style is not applied and it ends up not being stacked.
Either relax the selector or export the class/wrapper element to allow stacking things other than Compound avatars to enable wider reuse. Otherwise code ends up having to work around it and duplicate logic which can de-sync:
Element Web's FacePile looks like this:
It has an extra overflow tile "..." at the end which follows the stacking behaviour. Due to the styling of compound-web the style is not applied and it ends up not being stacked.
Either relax the selector or export the class/wrapper element to allow stacking things other than Compound avatars to enable wider reuse. Otherwise code ends up having to work around it and duplicate logic which can de-sync:
Partly caused https://github.com/vector-im/element-web/issues/26112