Praise be to Allah.
There is nothing wrong with making images of inanimate things such as trees etc, and that includes pictures of the Ka’bah and other sacred places, if they are free of images of human beings.
But the person who is praying should not have in front of him or on his prayer mat any kind of images, lest he be distracted by them. Al-Bukhaari (373) and Muslim (556) narrated from ‘Aa’ishah that the Prophet (peace and blessings of Allaah be upon him) prayed in a black cloak that had markings, and he looked at its markings. When he finished praying, he said: “Take this cloak to Abu Jahm ibn Hudhayfah, and bring me his plain garment, for they distracted me just now when I was praying.”. Hishaam ibn ‘Urwah narrated from his father, from ‘Aa’ishah that the Prophet (peace and blessings of Allaah be upon him) said: “I was looking at its markings whilst I was praying and I was afraid that they would distract me.”
The black cloak referred to (khameesah) is a striped cloak made of silk or wool.
The plain cloak referred to is a heavy cloak with no decoration on it.
It is makrooh to pray on these decorated rugs because that may distract the worshipper, not because of what is mentioned in the question about showing disrespect to the holy places by walking on the rug. It seems that there is no disrespect in that, rather these rugs are taken care of by their owners and they usually stand on the part that is free of these images.
Shaykh Ibn ‘Uthaymeen (may Allaah have mercy on him) was asked about the rugs on which there are images of mosques – can we pray on them? He replied: What we think is that a rug should not be set out for the imam on which there are images of mosques, because it may distract him and he may look at them which will affect his prayer. Hence when the Messenger of Allaah (peace and blessings of Allaah be upon him) prayed in a cloak that had stripes, he looked at the stripes when he finished and said: “Take this cloak to Abu Jahm ibn Hudhayfah, and bring me his plain garment, for they distracted me just now when I was praying.” Agreed upon from the hadeeth of ‘Aa’ishah (may Allaah be pleased with her).
If it so happens that the imam will not be distracted by that because he is blind, or because this is so commonplace to him that he will not pay any attention to it, then we do not think that there is anything wrong with him praying on it. And Allaah is the Source of help. End quote from Majmoo’ Fataawa al-Shaykh Ibn ‘Uthaymeen (12/362).
It says in Fataawa al-Lajnah al-Daa’imah (6/181): Question: What is the ruling on praying on carpets that contain drawings of Islamic buildings as in the case of the carpets that we see in mosques nowadays, and what is the ruling on praying on them if they contain crosses? When we want to judge whether it is a cross, does the lower portion have to be long and the upper portion short, and the two sides equal, or do we judge that whenever two lines cross perpendicularly that it is a cross? We hope that you can advise us about this matter because it is a common problem. May Allaah preserve you and take care of you.
Answer: Firstly: The mosques are the houses of Allaah, which were built for the establishment of regular prayer and so that Allaah might be glorified therein morning and evening with proper presence of mind, humility, focus and fear of Allaah. Decorations and adornments in the furnishings and on the walls of the mosque distract one from remembrance of Allaah (dhikr) and take away a lot of focus from the worshippers, hence that was regarded as makrooh by most of the salaf. The Muslims should avoid that in their mosques so as to protect their worship by avoiding distractions in the places where they seek to draw closer to Allaah, the Lord of the Worlds, in the hope of attaining a greater reward. As for prayers offered there, they are valid.
Secondly: the cross is the symbol of the Christians which they put in their places of worship and venerate it, and they regard it as a symbol of a false belief, which is the crucifixion of the Messiah ‘Eesa ibn Maryam (Jesus son of Mary, peace be upon him). Allaah has stated that the Jews and the Christians lied concerning that, as He says (interpretation of the meaning): “they killed him not, nor crucified him, but it appeared so to them” [al-Nisa’ 4:157]. So it is not permissible for the Muslims to use it in the furnishings of their mosques or elsewhere, or to leave it there; rather they should get rid of it and erase it and leave no trace of it, so as to avoid evil and avoid resembling the Christians in general and in their holy places in particular. It makes no difference whether the vertical line in the cross is longer than the horizontal line or it is the same, or whether the upper part of the two crossed lines is shorter or the same as the lower part. End quote.
And Allaah knows best.