You can increase the size of a ProgressView by using the .scaleEffect method:
AsyncImage(url: URL(string: video.poster_url)) { phase in
if let image = phase.image {
image
.resizable()
.aspectRatio(contentMode: .fill)
} else if phase.error != nil {
Color.red
} else {
ProgressView()
.scaleEffect(x: 2, y: 2, anchor: .center)
}
}
.frame(width: width, height: height)