Option Explicit
Const ksFactor As Double = 0.177346958265686
Const knMaxWidth As Long = 100

Sub Main()
    Dim pic As Picture
    For Each pic In Sheet1.Pictures
        pic.Delete
    Next pic
    Sheet1.UsedRange.Clear
    Dim row As Long
    Dim col As Long
    Dim dirName As String
    With Application.FileDialog(msoFileDialogFolderPicker)
        .Title = "Choose a directory"
        .Show
        If .SelectedItems.Count = 0 Then End
        dirName = .SelectedItems(1)
    End With
    Dim nFile As Long
    Dim sFile As String
    Dim sFiles() As String
    sFile = Dir(dirName & "\*.jpg")
    Do While Len(sFile) > 0
        nFile = nFile + 1
        ReDim Preserve sFiles(1 To nFile)
        sFiles(nFile) = sFile
        sFile = Dir
    Loop
    Dim nWidth As Long
    Dim nHeight As Long
    nWidth = Int(Sqr(nFile))
    nHeight = Int(nFile / nWidth)
    If nWidth * nHeight < nFile Then nHeight = nHeight + 1
    Dim nCount As Long
    nCount = 0
    For row = 1 To nHeight
        Dim nMaxHeight As Long
        nMaxHeight = 0
        For col = 1 To nWidth
            If nCount < nFile Then
                nCount = nCount + 1
                Dim picCurrent As Picture
                Set picCurrent = Sheet1.Pictures.Insert(sFiles(nCount))
                picCurrent.Top = Sheet1.Cells(row, col).Top
                picCurrent.Left = Sheet1.Cells(row, col).Left
                Dim nPicWidth As Double
                Dim nPicHeight As Double
                nPicWidth = picCurrent.Width
                nPicHeight = picCurrent.Height
                If nPicWidth > knMaxWidth Then
                    picCurrent.Width = knMaxWidth
                    picCurrent.Height = knMaxWidth / nPicWidth * nPicHeight
                End If
                nMaxHeight = Application.Max(picCurrent.Height, nMaxHeight)
                Sheet1.Cells(row, col).Value = sFiles(nCount)
                If row = 1 _
                Or Sheet1.Columns(col).ColumnWidth < picCurrent.Width * ksFactor Then
                   Sheet1.Columns(col).ColumnWidth = picCurrent.Width * ksFactor
                End If
            End If
        Next col
        Sheet1.Rows(row).RowHeight = nMaxHeight + 11.75
    Next row
    For col = 1 To nWidth
        Sheet1.Columns(col).ColumnWidth = Sheet1.Columns(col).ColumnWidth + 1
    Next col
End Sub