I cannot begin to fathom the logic of this.
I just added a comment to a task and uploaded a file. The little white rectangle that asana uses to indicate the file is only about 80% as wide as the space allows, so I cannot read the entire file name.
Worse than that, however, the files uploaded to the prior comment appear only abou 70% as wide as the new file (or about 56% as wide as the space allows).
Unless Asana has some unimaginable reason not to want me to see the full filenames, please make those elements as wide as the space allows.
And if the file name is too long to appear in even the widest allowable box, then please make the full file name appear when we hover over it.