I really cannot find the references the artist used to model these parts, ill have to dig deeper

there are two types of tiger II that saw usage in WWII:

the most common: Panzerkampfwagen Tiger Ausf. B
the command version, which had less ammo for more radios: Panzerbefehlswagen Tiger Ausf. B

the "grilles" are present on the Pz.Bef.Wg.Tiger Ausf.B but not the Pz.Kpfw. Tiger Ausf B, so i find it likely that the artists who made the model referenced the Pz.Bef.Wg.Tiger Ausf.B either entirely or primarily and thus the "grilles" appeared

there are also some irl pictures of Pz.Bef.Wg.Tiger Ausf.Bs where the "grilles" are visible, such as this one (and while its hazy, if you look closely you can make out the border of the "grilles")
https://www.worldwarphotos.info/wp-content/gallery/germany/tanks/konigstiger/Konigstiger_502.jpg
https://forum-en-cdn.warthunder.com/original/3X/8/b/8bcc7c28820a0f2d3f730ec060eab695407452e0.jpeg

both of these are of the same tank, but still

its also likely that this is only on early production examples, as im sure germany decided the extra grills werent essential to the design and thus cut it out in order to save on production and material costs

Originally posted by retro wave:

there are two types of tiger II that saw usage in WWII:

the most common: Panzerkampfwagen Tiger Ausf. B
the command version, which had less ammo for more radios: Panzerbefehlswagen Tiger Ausf. B

the "grilles" are present on the Pz.Bef.Wg.Tiger Ausf.B but not the Pz.Kpfw. Tiger Ausf B, so i find it likely that the artists who made the model referenced the Pz.Bef.Wg.Tiger Ausf.B either entirely or primarily and thus the "grilles" appeared

there are also some irl pictures of Pz.Bef.Wg.Tiger Ausf.Bs where the "grilles" are visible, such as this one (and while its hazy, if you look closely you can make out the border of the "grilles")
https://www.worldwarphotos.info/wp-content/gallery/germany/tanks/konigstiger/Konigstiger_502.jpg
https://forum-en-cdn.warthunder.com/original/3X/8/b/8bcc7c28820a0f2d3f730ec060eab695407452e0.jpeg

both of these are of the same tank, but still

its also likely that this is only on early production examples, as im sure germany decided the extra grills werent essential to the design and thus cut it out in order to save on production and material costs

I have found some pictures of Tiger 2 H non-command with grille like covers and one picture of a Tiger 2 P with a mesh grille cover on the vents. But most Tiger 2P don't have that.

Originally posted by st0815:

I have found some pictures of Tiger 2 H non-command with grille like covers and one picture of a Tiger 2 P with a mesh grille cover on the vents. But most Tiger 2P don't have that.

in the case of the tiger 2 Hs those likely are command ones, just missing the turret antenna or the hull antenna either through late war production struggles or battle damage, sometimes both could be missing especially on late 1945 examples, there were also two versions of the command variant that had different antenna setups

theres also plenty of pictures of known command variant tiger 2s missing one or both to back this up:
https://forum-en-cdn.warthunder.com/original/3X/8/b/8bcc7c28820a0f2d3f730ec060eab695407452e0.jpeg
https://forum-en-cdn.warthunder.com/original/3X/0/1/0198883a65c95c834e8ab40b53143d687a480c36.jpeg
(the grilles are also visible on both)

theres also the possibility that command hulls or turrets were put with regular variant hull or turrets towards the end of the war due to the resource and production strain, and then the hull antenna was removed or never installed since it didnt have the extra radios

as for the tiger Ps, porsche probably intended his hulls to have them but seeing as they didnt win the contact there was no reason to put them on the rest as they wouldnt see use; either that or the photos of the tiger Ps without them are just photos of before they were put on