The admin's environment check page checks many things including checking consistency of photos and thumbnails. Every record is represented by a dot and check result looks like:
..........................................ok
If there are many dots, then the page becomes very wide inside a browser which does not look well. There is a very simple way of breaking the dot sequence into more lines - just a space should be inserted after each dot:
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ok

So I recommend changing
admin/checkconfigs.php, line 216
(a little bit after "//CONSISTENCY CHECK" and "//check loop")

from:

echo "." ;

to:

echo ". " ;