On my macbook pro with second Monitor 3600,1260, I get only one window with large chessboard stripe left and right and some difficult to understand interaction!. Possibly also a problem of X11 (XQuartz)
The second window is hidden, a display problem. Still size is maximum enlarged!
OK, I’ve tried a workaround. Not a bugfix, but at least something to make it usable (as yesterday).
Could you try @Silvio_Grosso and @KaRo a $ gmic update and another try, to see if that makes things better ?
The 2 images (landscapes) are one of top of the other and it is somewhat possible to grab their border in order to resize them.
EDIT: actually, grabbing the border of the image above is quite difficult to say the least…
Here is the screenshot (Asus, with the monitor of 13,3 inches):
Hmm, the second window disappears with that display problem I know from Quartz. After some ^C and moving around I get the windows both visible. As I said this is IMHO an X11 problem of the Mac XQuartz!
On my Mac the width of the monitor(s) is the ruling factor. Without 2. monitor eg lena,leno dp appear nicely side by side. Size : 1680,1028
With landscape sample its top/bottom!
With the second monitor and large width the position of the second window is difficult, with landscape image as well as lena/o the title line is outside mouse access! With help of the mac window manager it is possible with some difficulties to get the two windows side by side.
What is a strange is that yesterday, when you first released this option I have tested it on Windows 10 with many images (side by side) and it worked extremely well…
Today’s “improvements” have some nasty side-effects on Windows
As an aside, there is a “famous” french scientist (probably a fraud…) that I recall quite well for his controversial pubblication on Nature:
Works well. Tried to scale it to more images. When at 3x3, the title bars of the top row is above the screen and the bottom of the bottom row is below (as to cut off the info). At 2x2, only the title bars are affected.