If I could give you a tip, it would be on the glossiness/specular maps. It's way too shiny. For example, the cushion on your chair, you computer screen and the metal/plastic parts on the chair all have the same level of Glossiness. Even for a cartoon-ish scene, it's better to have some diversity in your shaders. More pleasant to look at. I must say, I still have trouble getting the right shaders in Sketchfab, so it's really trial and error. Never leave anything at 100%, except if it's a mirror.
Another thing, I hate empty spaces. I always pack up my scenes with tons and tons of props and accessories to give it more life. It takes double the time to set everything right, but I never regretted it. If I was you, I'd fill my scene a little more. You have this big counter with almost nothing on it. Science labs have a lot to offer: computers, scientific instruments, tools, etc. And when the counter is filled, you go on with the floors, then with the walls, then with the celling even. The more the better as long as you keep the same quality everywhere. Though that's just me, you may want to take the more minimalistic route, and that's perfectly fine too.
Overall great scene, it's great to see another student in the best field of work ever.