On my machine I tested it with consistently sized text (first word same as rest of paragraph). Since your document has a differently sized first word you are getting an offset. Therefore the code would need to be adapted to position the frame higher and the size of this offset will vary depending on the relative size difference of first/rest of paragraph.
This is my attempt to show what might work. I've included a line so it is easier to see where the frame is. That line could be disabled/removed once you have it working correctly. You may need to fiddle with parameters to get the offset that works for your specific sizes and typefaces.
Code:
Sub DropCapMeHebrew()
Dim aFrame As Frame, aPara As Paragraph, aWord As Range, iOffset As Integer
For Each aPara In Selection.Range.Paragraphs
If aPara.Range.Frames.Count = 0 Then
Set aWord = aPara.Range.Words.First
iOffset = aWord.Font.Size - aPara.Range.Words.Last.Font.Size
Set aFrame = ActiveDocument.Frames.Add(Range:=aWord)
With aFrame
.Borders.OutsideLineStyle = wdLineStyleNone
.HorizontalDistanceFromText = 2
.Shading.ForegroundPatternColor = wdColorAqua
.RelativeVerticalPosition = wdRelativeVerticalPositionParagraph
.VerticalPosition = .VerticalPosition - iOffset
End With
End If
Next aPara
End Sub