message: image field: scale to row height, show border
diff: @@ -24,13 +24,13 @@ const useStyles = makeStyles((theme: Theme) =>
  display: "inline-block",
  cursor: "pointer",
  - height: 32,
  - width: 42,
  -
  backgroundSize: "contain",
  backgroundPosition: "center center",
  backgroundRepeat: "no-repeat",
  + boxShadow: `0 0 0 1px ${theme.palette.divider} inset`,
  + borderRadius: theme.shape.borderRadius,
  +
  "& + &": { marginLeft: theme.spacing(1) },
  },
  @@ -43,6 +43,8 @@ const useStyles = makeStyles((theme: Theme) =>
  backgroundColor: "rgba(255,255,255,0.8)",
  color: theme.palette.text.secondary,
  + boxShadow: `0 0 0 1px ${theme.palette.divider} inset`,
  + borderRadius: theme.shape.borderRadius,
  opacity: 0,
  transition: theme.transitions.create("opacity", {
  @@ -128,7 +130,11 @@ const Image = (props: Props) => {
  onSubmit(value);
  }}
  className={classes.imgContainer}
  - style={{ backgroundImage: `url(${file.downloadURL})` }}
  + style={{
  + backgroundImage: `url(${file.downloadURL})`,
  + width: row.rowHeight * 0.9,
  + height: row.rowHeight * 0.9,
  + }}
  >
  <Grid
  container
  