Outdoor placed inside

I was given this outdoor seedling from a friend, I transplanted it and put it inside under 24 hour light. The next morning it appears to have this bit of silver dots on the leaves.

Any ideas why that would occur?

Hot soil? What is it in?

Well when it came to me it was in normal top soil that my neighbor used. The super soil seller told me I can transplant to their product after a couple sets of leaves so that's what i did. Its nutrient rich so that might explain but I was hoping a seedling this size can handle super soil.

Maybe wrong? Maybe stress from that and or suddenly getting more light and a co2 infused warm environment?

I had similar issue when I transplanted into my ss. Ended up being fine in the long run. I'd guess that's what it is, I am still a newbie tho.

Any pros recommend to dial down the way I push these babies so as to avoid general yellowing or shock of super soil? I been on one hell of a struggle with yellowing and unhappy roots while pushing seedlings. Actually did dial back a couple weeks ago and it seemed to make no difference.

Super soil burn is weird and annoying. I hereby declare that it SS is no longer allowed to burn seedlings. Or lockout nutes.