Seedlings do not need high humidity or humidity domes, domes just encourage disease, weak growth and you risk cooking them.
Plants do not take water in through their leaves, plants just don't work like that...all the water is sucked up via the roots.
Your seedling looks normal to me, the cotyledons (small rounded leaflets) fold back to expose the growing tip where the first true leaves will be emerging from in a day or two.
Keep her moist, be patient and soon enough you should have a happy seedling.