Looks good to me as algeriensis though the sunlight makes it difficult for me.
When I birded in Libya we got both elegans and algeriensis in the west of the country.
Your bird appears too dark for elegans allowing for the sun's angle.
Your bird has a larger black bridge on the forehead than average but I did see some with it.
I don't
think any wintering great grey shrike match as well as algeriensis but I don't have so much experience with them.
Hope this helps
Rob
www.birdingforalark.blogspot.com