ベクトルとラスター画像の境界が不明です。

@pilo51 first of all the questions were very confusing, ChatGPT likely gave you the answers which is likely correct.

1. 'simply want to vectorize the created object.' — If your goal is to "vectorize the created object" and that object currently exists as a raster image (like a JPG or PNG), then using "Image Trace" in Illustrator (or similar features in other vector software) is the primary method to convert that raster image into a vector shape. After performing the Image Trace, you must then "Expand" the result to convert the traced paths into editable vector shapes and fills. 
   
   
2. Divide Appearance?  — I think you mean Expand! When you apply certain effects, brushes, or live text in Illustrator, they are "live" or "dynamic." This means they can be easily edited. "Expand Appearance" (or "Expand") takes these live effects/objects and converts them into editable paths and fills. It "bakes in" the appearance. If "Expand Appearance" is greyed out, it means the selected object doesn't have an "appearance" that can be expanded. This typically happens for very basic shapes (simple fills and strokes) that are already just paths and fills without any special effects applied. If you draw a basic rectangle and fill it with a solid color, there's no "appearance" to expand because it's already as "expanded" as it can be. Simple fills and strokes are vector. They are defined by paths. You can tell if an image is raster by zooming in heavily – if it pixels, it's raster. If the edges remain perfectly smooth, it's vector. Another hint is looking at the 'links' panel, if there is an image it may say what it is:
   

   And if you view in Outline View (Command Y on a MAC) (Control Y on a PC)

   

   
   
   You will see the nodes, paths, and anchors (vectors) and the image as an X (raster). Just click (Command Y on a MAC) (Control Y on a PC) to go back to Preview Mode again
   
   

3.  Split and merge the transparency — "Flatten Transparency" (Object > Flatten Transparency) is primarily used to process transparency interactions (like overlapping objects with different opacity settings, blend modes, or certain effects) into a simpler format. This can involve rasterizing parts of your artwork, especially if complex transparency or blend modes are involved. It's not directly for vectorizing existing raster images. Instead, it's about preparing your existing vector artwork (which might have transparency) for output.
   
   
4.   "Blur" is rasterized. "Gradient" is a vector. — Correct. Any blur effect (Gaussian Blur, Radial Blur, Motion Blur, etc.) is a raster effect. If you apply a blur to a vector object in Illustrator, that portion of the object (or the entire object, depending on the effect and settings) will be rendered as pixels. This is precisely why your Adobe Stock submission was flagged. Gradients in Illustrator are vector-based. They are defined mathematically as a smooth transition of colors within a shape. You can apply a gradient to any vector shape, and it will remain infinitely scalable. 
   
   Let's circle back to Adobe Stock, your said file contained raster images— This means that even though you were working in Illustrator (a vector program), some elements within your file were not true vectors. For example, you might have placed a JPG or PNG into your Illustrator file. Effects like "Gaussian Blur," "Drop Shadow" (if not set up carefully), "Feather," and some Photoshop Effects (from the "Effect" menu > "Photoshop Effects") are raster-based. Even though applied in Illustrator, they will rasterize the part of the artwork they affect.And including Image Trace, you can attempt to convert raster to vector, the output itself might still contain raster areas if not carefully refined.