Huge Wallch icon in Xubuntu 14.04 (xfce-panel)

I have strange problem. My Wallch icon is huge. See the screenshot:

I removed XFCE settings and reordered items a little. How can I restore normal Wallch icon size?

Update:

My /usr/share/applications/wallch-nautilus.desktop file:

[Desktop Entry]
Version=4
Name=Wallch
Comment=Change desktop wallpapers automatically
Exec=/usr/bin/wallch %U
Icon=wallch
Terminal=false
Type=Application
Categories=Utility;Application;
MimeType=inode/directory;

Actions=Change_Wallpaper;Start;

[Desktop Action Change_Wallpaper]
Name=Change Wallpaper Once
Exec=/usr/bin/wallch --change
TargetEnvironmet=Unity

[Desktop Action Start]
Name=Start/Stop Wallpapers
Exec=/usr/bin/wallch --start
TargetEnvironment=Unity

And the /usr/share/pixmaps/wallch.png:

I was able to set my wallch icon size to normal. How I did that:

1. Opened /usr/share/wallch/files/indicator_radiance_normal.png in Gimp.
2. Resized it to 24x24. Saved the original as indicator_radiance_normal_64x64.png and the edited as indicator_radiance_normal.png
3. Restarted Wallch.

Now it looks exactly how it should:

Also, I posted bugreport and it came out that it is not a Wallch bug, but xfce4-indicator-plugin bug.