How to place two images from clipboard side by side?

[Peter2]

Maybe I missed it for a long time, but I'm still not sure what the best "workflow" is to place two snippets (images from clipboard) side-by-side.

I have "Snipp_a" and "Snipp_B", both not saved image in XNView.

Now I want to arrange them side by side, e.g.

"AB" or
"BA" or
"B
A".
In MS Paint there no problem, but in XnView I missed something ....

[xnview]

you need to save them and use 'compare'