I had a look at their original page and it looks really good from a design point of view. Your Codepen looks nice but I think it moves away from what the company is focusing on displaying to their customers at the moment.
From their original website, they are clearly focusing on green and a lot of white and whitespace. You are using some greys and gradients that might be taking away from the modern, simple look they seem to be looking for.
There’s also a lot of produce and people. They want to showcase fresh products and a personable approach where you can talk to your delivery person. This is quite normal for companies that work mainly with online shopping. The idea of the lemons is good but I think for their business image they might be looking for images with more produce and people on them.
I assume (without any experience in UX/UI) that companies do want you to innovate on their websites but more than that they want to see that you understand their business idea, what they want to sell and who they want to sell it too.
I assume your page is more like a wireframe than a functional page, I guess it is more graphic design oriented than a web page.
Again, your Codepen looks great but it will definitely be compared to what they already have, which is a pretty nice website already.
Maybe also working on their website and solving the problems in it that you’ve found could be a great way to present your development skills and prove you’re a problem solver.
Hope it helps, good luck with your interview!