Should `unlist` for a `list` of `image-magick` work like `image_join`?

[KaiAragaki]

It's been alluded to previously (#158, #330), but there seems to be a certain amount of confusion with lists of images vs a vector of images. I was recently confused by this too, as I expected image_vector and image_list to yield similar results:

library(magick)
image_vector <- c(wizard, wizard)
image_list <- unlist(list(wizard, wizard))

image_vector
#> # A tibble: 2 × 7
#>   format width height colorspace matte filesize density
#>   <chr>  <int>  <int> <chr>      <lgl>    <int> <chr>  
#> 1 GIF      480    640 sRGB       FALSE    99674 72x72  
#> 2 GIF      480    640 sRGB       FALSE    99674 72x72  

image_list
#> [[1]]
#> # A tibble: 1 × 7
#>   format width height colorspace matte filesize density
#>   <chr>  <int>  <int> <chr>      <lgl>    <int> <chr>  
#> 1 GIF      480    640 sRGB       FALSE    99674 72x72  
#> 
#> [[2]]
#> # A tibble: 1 × 7
#>   format width height colorspace matte filesize density
#>   <chr>  <int>  <int> <chr>      <lgl>    <int> <chr>  
#> 1 GIF      480    640 sRGB       FALSE    99674 72x72  

image_join works great, but I found this behavior a little surprising.

Thanks for the great package!