You can get the image Height and Width by using by setting a reference to:

Microsoft Windows Image Acquistion Library v2.0

dll can be obtained here at Microsoft Download Center

http://tinyurl.com/3pc836

There are probably other ways to get the information, but this is how I did it.
I also use this dll to resize a directory of pictures and make thumbs out of them.
The download comes with a help file.

There is an issue of resizing when I try to resize your smaller pic size to the larger size I only get 862x647 the same can be said of the reverse. This is probably due to it maintaining the aspect ratio.

Beats the heck out of doing manually

Something like this you may have to tweak it:
[vba]Dim jpgImg As ImageFile
Set jpgImg = CreateObject("WIA.ImageFile")

For Each file In Folder.Files
If (LCase(Right(file, 4)) = LCase(FileType)) Then
For Each file In Folder.Files
If (LCase(Right(file, 4)) = LCase(FileType)) Then

With ws.Cells(iCurrentRow, iColumn)
jpgImg.LoadFile file.Name
.Value = file.Name
.AddComment.Shape.Fill.UserPicture file.Path
.Comment.Shape.Width = jpgImg.Width
.Comment.Shape.Height = jpgImg.Height

iCurrentRow = iCurrentRow + 1
End With
[/vba]