All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
Evidently – and Allaah Knows best – it is permissible to upload the picture of the Ka‘bah or the Masjid An-Nabawi to press "Like" in admiration of it; there is nothing wrong with this. They are the most deserving things for a Muslim to admire and there is no doubt that they are beautiful.
However, beauty is a relative matter; what some people consider as beautiful in appearance may not be considered as such by someone else. This does not imply having incomplete faith. There is also no sin on the person if he does not press “Like”.
Assuming that the picture of the Ka‘bah is not beautiful, then beauty is not necessarily the beauty of the picture; rather, finding it beautiful and admirable is because of its prestige and greatness in one’s soul, and because of what you mentioned that it is a symbol of Tawheed and unity of the message of Islam; it is a place of return and a place of security for people. Prophets set out to it as pilgrims and they performed Tawaaf (circumambulation) around it in addition to all the other virtues of the Ka‘bah as reported in Islamic texts.
We have already clarified that it is permissible to hang a picture of the Ka‘bah at home even if there are people in it performing the Tawaaf if the people appear small and the features of each individual are not clear. For more benefit, please refer to Fataawa 269941 and 83423.