Ruling on giving perfume to worshippers whilst the khateeb is sitting on the minbar
Question

                When the imam comes in and sits on the minbar, is there anything that may invalidate the prayer? 

Because one time a Muslim sat down beside me and gave me a small bottle of perfume, and gestured to me that I should put some perfume on me then pass it to the person next to me, and so on. I was worried and thought to myself that perhaps my prayer was invalidated in that case. 
When I enter the mosque I pray two rak’ahs, but what should I do if the iqaamah for prayer is given when I am still in the first rak’ah?.
Praise be to Allah.What the one who attends 
    Jumu’ah should do is listen attentively to the khutbah and it is not 
    permissible to busy himself with anything else, because the Prophet  
    (peace and blessings of Allaah be upon him) said: “If you say to your 
    companion, ‘Listen attentively’ on a Friday, when the imam is delivering the 
    khutbah, then you have engaged in idle speech.” Narrated by al-Bukhaari 
    (934) and Muslim (851). 
And he said: “whoever 
    touches the pebbles has engaged in an idle action.” Narrated by Muslim 
    (857). 
Al-Nawawi said in Sharh 
    Muslim: 
This shows that it is 
    forbidden to touch the pebbles or fidget in any other way during the 
    khutbah. It also indicates that one should focus mentally and physically on 
    listening to the khutbah. What is meant by idle actions here is something 
    that is false, blameworthy and rejected. End quote. 
Giving perfume to the 
    worshippers at the time of the khutbah distracts them from listening to it, 
    and it is like the touching pebbles that is mentioned in the hadeeth. 
The prohibition on speaking 
    and fidgeting on Friday applies only when the khateeb begins the khutbah, 
    until he finishes it. 
But at the time of the 
    adhaan and when the imam sits on the minbar, it is not haraam to speak, 
    because of the meaning of the hadeeth quoted above: “If you say to your 
    companion, ‘Listen attentively’ on a Friday, when the imam is delivering the 
    khutbah, then you have engaged in idle speech.”  This clearly shows that the 
    ban on speaking only applies whilst the imam is delivering the khutbah. 
At the time of ‘Umar ibn 
    al-Khattaab (may Allaah be pleased with him), when ‘Umar came out and sat on 
    the minbar, and the muezzins gave the adhaan, the people would sit and talk 
    until the muezzins fell silent and ‘Umar stood up, then they would fall 
    silent and no one would speak. This was stated by Imam Ahmad, Maalik, and 
    al-Shaafa’i (may Allaah have mercy on them). 
See: al-Mughni 
    (2/86). 
Shaykh Ibn Baaz (may Allaah 
    have mercy on him) was asked: When is it forbidden for a person to touch the 
    pebbles or use the miswak during Jumu’ah prayers? Is it from when the imam 
    ascends the minbar or from the beginning of the khutbah? Because I see many 
    people who do not stop using the miswak until after the imam begins the 
    khutbah. And some of them use it during the khutbah. 
He replied: The Sunnah is 
    to listen attentively to the khutbah and not use the miswak or fidget in any 
    other way, from the moment the khutbah starts until it ends, in accordance 
    with the saheeh ahaadeeth that have been narrated concerning that. 
But if a person enters the 
    mosque whilst the imam is delivering the khutbah, then he should pray 
    tahiyyat al-masjid (two rak’ahs to “greet the mosque”) before sitting down. 
The Prophet  (peace and 
    blessings of Allaah be upon him) said: If one of you comes on Friday and the 
    imam is delivering the khutbah, let him pray two rak’ahs but make them 
    brief. End quote from Fataawa al-Shaykh Ibn Baaz (12-336). 
Based on that, there is 
    nothing wrong with giving perfume to the worshippers before the imam starts 
    his khutbah. But once he starts it, then one must stop doing that and listen 
    attentively to the khutbah.
    Secondly: 
If the iqaamah for prayer 
    is given when you are in the first rak’ah of “greeting the mosque” or a 
    regular Sunnah prayer, then you should stop that prayer and join the 
    congregation. 
This has been discussed in 
    the answer to question no. 33582. 
And Allaah knows best.