hmmm... I see...
That would be convenient for me, too.
Other than the Right Click Menu > Open With option, I am not aware of any applet for the panel that does that.
XFCE can stack multiple apps in one launcher, but not for choosing from Pictures like that. Rather, you would choose which app to open from the launcher, then within that app, open your file.
Let me log in on Cinnamon D.E. and test this a bit.