IssueTracker

Assuming that the ic_android.xml asset is the following one:

<vector xmlns:android="http://schemas.android.com/apk/res/android"
        android:width="24dp"
        android:height="24dp"
        android:viewportWidth="24.0"
        android:viewportHeight="24.0">
    <path
        android:fillColor="#FF000000"
        android:pathData="M6,18c0,0.55 0.45,1 1,1h1v3.5c0,0.83 0.67,1.5 1.5,1.5s1.5,-0.67 1.5,-1.5L11,19h2v3.5c0,0.83 0.67,1.5 1.5,1.5s1.5,-0.67 1.5,-1.5L16,19h1c0.55,0 1,-0.45 1,-1L18,8L6,8v10zM3.5,8C2.67,8 2,8.67 2,9.5v7c0,0.83 0.67,1.5 1.5,1.5S5,17.33 5,16.5v-7C5,8.67 4.33,8 3.5,8zM20.5,8c-0.83,0 -1.5,0.67 -1.5,1.5v7c0,0.83 0.67,1.5 1.5,1.5s1.5,-0.67 1.5,-1.5v-7c0,-0.83 -0.67,-1.5 -1.5,-1.5zM15.53,2.16l1.3,-1.3c0.2,-0.2 0.2,-0.51 0,-0.71 -0.2,-0.2 -0.51,-0.2 -0.71,0l-1.48,1.48C13.85,1.23 12.95,1 12,1c-0.96,0 -1.86,0.23 -2.66,0.63L7.85,0.15c-0.2,-0.2 -0.51,-0.2 -0.71,0 -0.2,0.2 -0.2,0.51 0,0.71l1.31,1.31C6.97,3.26 6,5.01 6,7h12c0,-1.99 -0.97,-3.75 -2.47,-4.84zM10,5L9,5L9,4h1v1zM15,5h-1L14,4h1v1z"/>
</vector>

It looks like the size given to the Image composable is larger than the intrinsic size of the vector asset (56dp vs 24dp). By default ContentScale.Inside is used on the Image composable which will shrink down the size of the VectorAsset if the destination size is smaller than that of the defaults of the VectorAsset itself. However, if the destination is larger than the intrinsic size, no scaling is applied which is why the size of the icon does not change. To verify I created the following composable:

        Image(asset = vectorResource(id = R.drawable.ic_android),
            contentScale = ContentScale.Fit,
            modifier = Modifier
                .drawBackground(Color.Gray)
                .size(size.value)
                .clickable(
                    onClick = {
                        if (size.value == 56.dp) {
                            size.value = 300.dp
                        } else {
                            size.value = 56.dp
                        }
                    }
                )
        )

By changing the ContentScale here to ContentScale.Fit, this will scale the VectorAsset to the bounds of the composable. Clicking the Image here will toggle the size between 56 and 300dp and verified that the VectorAsset is scaled accordingly.

TLDR use ContentScale.Fit instead of the default of ContentScale.Inside.

I've tried ContentScale.Fit, and it worked well. Thank you for explaining that

Thanks for filing this ticket. After some additional thought we have decided to change the default ContentScale parameter to be ContentScale.Fit instead of inside. This would make the original code example work as expected without having to be explicit. Usually when a default size is provided, the intention is the scale the content accordingly either up or down. This does not change the default behavior if no explicit size is provided.