see the shiny :( what did i do wrong? I didn't touch the size of the embroidery....

Did you tape the mylar to the top & bottom of the of the frame. If you did you shouldn't have any problem. I just did a couple & and are sparkly.

IRIDESCENT EMBROIDERY FILM© can be used in designs that have a loose weave. I have specifically created two collections (so far) to utilize this magnificent film, All that Glitters – Mermaids, and All that Glitters – Angels. In the sample shown, the base layer of the mermaid tail is stitched, then the film applied, and open weave stitches applied on top to allow the film to show through.
Did you read this? It was written under the mermaid picture.

I am not sure what it is you are asking. I am making a assumption. If you are doing the Meermaid you place the Mylar before you start the 3rd color. which makes the body glitzy. See the pdf file that goes with it. I haven't done it myself yet, but this is what is different from any other design.