Last modified: 2013-11-13 18:17:28 UTC
The text-box has a fixed height of 44px, and then expands as the content within requires. However, we need a better default for people without javascript. For those users, it would be sensible to go somewhere closer to the current mediawiki default, which is 25 lines of monospace. We suggest 10 lines, would be a good default, for editing Flow posts and Board headers. Note: 10 lines of text seems to be approximately 240px high, in Flow.
The WMF core features team tracks this bug on Mingle card https://mingle.corp.wikimedia.org/projects/flow/cards/424, but people from the community are welcome to contribute here and in Gerrit.
Fixed in https://gerrit.wikimedia.org/r/#/c/95052/