Looks like some nice healthy roots, for both systems. I am guessing the tomato's are fairly new considering the much smaller root systems. And the Japanese Cucumbers look like they are quite healthy. Although I would have two concerns. One is the nutrient reservoir don't look light proof. That is, the plastic containers look translucent. The second one is possible high nutrient temperatures, being in the direct sunlight, as well as sitting on what looks like cement that absorbs all the suns heat.

Looks good, keep an eye on the water temp also. If it gets hot it can cook the roots, or too cold it can do damage to the roots.

The light is a good point to, keep it dark in there.

The rez isn't completely opaque. One thing you might consider for both preventing light penetration and controlling heat is some foil faced insulation. The type for putting under siding. I've started using it and it works perfect. Plus, it protects from UV degradation of the plastic. Just a suggestion.