Grandma get to play with Thin Lizzy

[Pekka]

True!
Thin Lizzy had a somewhat erratic policy of including members in the artwork.
The Jailbreak sleeve had two different versions: one with four characaters (the bandmembers) running in the tv screen frame. And one with only three.

The original Vertigo vinyl (9102 008) had a die-cut gatefold sleeve and when opened the whole band is visible. I recall reading that the record company wanted Jim Fizpatrick to make the band picture bigger and because of this one member went out of sight. The later pressings without the die-cut gatefold have had alternately 3 or four members visible. The first CD on Vertigo had three, the remaster on Mercury had four and the latest deluxe double has again three.

And the front sleeve of Bad Reputation did not feature Brian Robertson although he had just rejoined the band when the album was released.
On the back of the sleeve they did include him in the picture.

He is also featured in the inner sleeve photos. I believe that front cover was Lynott's way of getting Brian back in line. He plays only on 3 songs on that album.