My 2 cents and impressions from the video. (Take them for what they are worth to you.)
1. Let her nose out and let her figure out how to stretch and carry herself. She is moving like a morgan show horse which means she's going to "pose" (as you called it) and not really reach for the contact. Let her have some space to stretch in to and then let her develop the muscles to carry herself there. She will learn that she doesn't always have to carry herself bundled up in to a little ball.
2. Relax your arms and elbows a little bit to help with #1 above. Create a nice soft contact for her to seek out.
3. Keep contact with your lower leg, but you don't have to have much pressure there at all. She's a morgan. She WILL move off your leg too quickly for a while until she learns what you want. The key is not to overreact and bring her back with your hands. Slow your posting and let her go until she accepts the contact AND keeps the tempo you want. This step can take a while, but eventually she will learn to distinguish between steady contact and a cue to move off your leg. (This one took a lot of patience on my part for my morgan mare to accept so we could work in a 2 point position w/o her rushing off every time. A big reason is that a lot of morgans are ridden with NO lower leg contact. It stems from the saddleseat roots I think. I have lots of friends who I show with on the morgan circuit and you should see all the gripping knees and lower legs completely OFF their horse in ALL the classes.)
4. She is a cute mare and she seems to really be trying for you. Keep having fun.
5. Lots of transitions seem to help with my mare. Don't overschool the same exercises too many times in a row. If she does it right, praise her and move on. She'll remember. Build on your successes in small steps. They'll add up.