Steve resolutely refuses to consider the amount of leg flexibility and strength to pull off some of the positions he's seen Clint stay in for extended periods of time. He's not drawing that, dammit, and he doesn't want that level of distraction.

It's actually not a real issue. Once Clint settles to work, so does Steve and his focus on it turns pretty complete. His position shifts here and there - leaned over the table, head propped in his hand, leaned back in his chair with one knee braced up by the table and sketchbook against his upraised thigh, whatever - but he doesn't actually stop.

What he's drawing really is Clint. Clint as he is now, complete with incomplete tattoo on one arm, slightly too long hair, faint lines around his eyes, even the bruising on his face, but... that exact moment he got excited about Steve's memory or art or whatever it was. Not... shut off and cold but that moment of life he'd had. Getting that into a set of eyes in grayscale and pencil is by far what takes the most time and is also the last thing he does and finishes.

And Clint's confused Steve cares about him as a person. ...that picture would look very different, if Steve didn't.