Thanqol Learns 2 Draw: Every Step Is The First

[Elemental]

I assume it's stained glass?

A few points to keep in mind..
Assuming the black lines represent the lead joins, the eye due to the physical properties of glass and how it's crafted make it physically impossible. It would have to be painted on.
Secondly, large areas are best subdivided into smaller segments as large pieces are almost impossible to make without them shattering. I suggest using thinner lines to do that so as to preserve the image.
And there was a third point that was supposed to go here... Something to do with colours and how hard it is to do different ones uses natural mineral pigments... But it does pay to mention that the craftsmen tried for vivid colours as that was what the people paying them favoured and it best showed their expertise.
Finally, a background of either clear glass or blue would be a better choice.

Of course, if it this isn't supposed to be stained glass and instead something else, then this is completely useless to you.