It's called "Der verlorene Handschuh" (The Lost Glove) painted by Carl Strathmann (1866-1939)
I got it out because I keep losing my gloves! I lost one in January, (I replaced the pair), but then I lost another in March (the right one AGAIN so I couldn't use the extra one I had)--and then lost another a week later (luckily the left one).
No gloves in the stores at this time of year. So I'm wearing a mis-matched pair.
At least they're both black.
The only good thing to come out of this silliness is that I got out this postcard again and remembered how much I liked it.