The image posted to the Russo Brothers Twitter account appears to show Joe Russo, one of the co-directors of Avengers: Infinity War and Avengers 4, sitting in a chair in a mostly empty sound stage looking at his laptop.
Russo’s chair looks to be in front of some frames on easels that might contain concept art, but the angle is bad so we can’t really see.
It’s a black and white image, which does a lot of work in potentially obscuring items of interest, but at first glance, there doesn’t seem to be a lot here.
The picture is also taken from much too far away to be able to see what Russo is looking at on his computer, though it could be an Avengers 4 script page or a clip from the dailies.