... Your medium is wet and condensation is forming in your cups. Do not use a dome, you risk your seedlings damping off. Get a little air circulation. Add 15-30ml when your cups get very light and more until moist, not wet. Good luck Jadxsushi
OP:
You should put another solid colored cup or some tap or something to block the light from reaching the inside of your soil. Once the roots start to grow and reach the edges of that cup the light will do some damage. Can you tell us about what you used for soil though? That does happen to look like really fine soil particles, after a bunch of waterings that could become very compact and cut off vital oxygen to roots.... Depending on your soil mix that you're using, you may want to consider adding something for aeration into the dirt before you transplant up to the next size pot.
Jadxsushi: I think the reason you're noticing the condensation is because its a clear cup, sun/light/heat/whatever is evaporating and cant escape, as long as you dont keep watering it, give it time to use up any remaining water from last feed.. (Let the roots grow and search for more water, dont let them wilt... but a nice dry out period is better than constantly supplying water on like a drip system or something.), As for the condensation: I think its a good sign actually, shows there are air pockets in your medium which is a good thing and any water stuck inside the medium there should redistribute itself back into the soil as the surrounding soil dries. I dont think people ever really notice it because no one really uses clear plastic. so they dont ever see it.. I will sometimes use a clear cup for the soil and a solid colored cup on the outside so you can take off the 2nd one, look at the root development, and put it back on to continue blocking the light.