Placed 1-bit images with/without a mask are not warping.
A file has placed bitmap images that are masked and when using the Conical Warp feature from Toolkit for Labels in Adobe® Illustrator®, they will not warp.
This is a limitation of the Envelope Distort function in Adobe® Illustrator® which the Conical Warp tool uses. Bitmap images cannot be warped.
Open the bitmap image in an image editor, like Adobe® Photoshop® and change it to either a grayscale or CMYK file. Next re-link the placed bitmap to the converted image in Adobe® Illustrator®. The image should now warp as expected.