Your seedling looks perfectly fine, some seedlings just take a bit longer to get going, usually making good roots before taking off.
Your seedling, or anybody elses, does not need a sweat lodge/humidity dome or spritzing with water.
Cannabis is not a rain forest plant, it actually prefers a dry climate.
By using a sweat lodge/dome, you risk cooking your seedling and/or encourage moulds/fungus to attack, they both love warm and humid.
Your seedling needs good air exchange for optimum growth, something that is not available under a dome or cover.
The only time cannabis NEEDS extra high humidity is when they are cuttings/clones, as they do not have roots at first, otherwise atmospheric humidity is more than adequate. Spraying your seedling often with water will/can lead to fungal attack and is unnecessary, your plant does not need it.
The whole humidity thing is an outdated practice from the 1960s when no one knew how to grow cannabis properly and GIs were bringing back Sativa type pot from Vietnam/Cambodia/Laos etc, so everyone thought "jungle", but cannabis is cultivated far far away from any jungle and only in the "dry season".
Indicas come from the Middle East, from countries like Afghanistan, Pakistan, Morocco etc, and I doubt anyone would associate these countries with any sort of humidity, in fact just the opposite, very dry and hot.
No need to worry, your plant will get going soon enough, just don't suffocate it with a cover or drown it with water.
Each and every plant is an unique individual organic being that will dance to the beat of its own drum and can not be compared to other plants growing in the same set up or identical conditions. It will do its own thing. Only clones are directly comparable as to growth rates etc.
Hope this helps,.........
Organoman.