Just an egg or is it something else

This looks like a snapshot in an exhibition of modern art. The lighting is almost typical to such exhibits... Top spot lighting always gives strong contrasts even when using a secondary more diffuse source to fill the space. Your choice was to hide in full shadow the only side of the object that would have given a clue what this object really is. I played with this type of still photography as well while working for a lighting company.

You decided to make this object somewhat intriguing letting the viewer guess: is it just a shell or a solid object? To add more mystery you could have done it entirely in B/W (see may attachment). Without colors it would have been even more intriguing. On the other hand, I must admit that the color of the shell is interesting and appealing in the context.

I would straighten the vertical line by rotating CCW about 3° and crop to eliminate the right corner.

Otherwise, a nice still life photo well executed that triggers the viewer attention.

Good job! Thanks for sharing and welcome in the Photo.net community.