Day 6 - Stretch

Your plant is only beginning to set it's first pair of true leaves. I think you are seeing normal growth. I personally don't use humidity domes much. My natural humidity is above 40% anyhow and a dome can cause other issues if you are not careful. When I do use a dome I put it on when I plant the seed to cut down on watering need and I remove it when the plant is about your size. I don't want the plant to become reliant on "perfect" and I want it to toughen a bit to handle normal growing condition fluctuations. I am a bit concerned that I don't see the top of your pot in the photos. It doesn't make sense to buy a 10 gallon pot and only put 7 gallons of soil in it. If done properly the more soil means a large plant able to produce more yield. By not filling your pot you are essentially using a smaller pot size. And, the soil level will drop during the grow leaving even more unused pot at the top.