Bilal bhai, though as you said the attendance may be three but the TV and the flags are an much as investment of the BJP as that by the Communist Party of India ( Marxist ) for airplane tickets and a high-end phone for Kanhaiya Kumar.
BJP will always go to the grassroots. Before loksabha election at the village level list of people who benefitted from any central government schemes was prepared and they were used as on-the-ground mouthpieces of the party. A Modi or Amit Shah may address a rally for thousands of people but many people may not be able to hear it. A Janakibai would go door to door and tell her neighbours that she got an LPG cylinder under the Ujwalla Yojana.
People like
@xeuss,
@ChennaiDude or
@The_Showstopper would call her a Sanghi and lament the death of secularism when BJP wins the election. They fail to understand that BJP doesn't win only on basis of anti-muslim rhetoric, the Janakibais and Hansmukhlals who benefitted from various schemes prove to be a very crucial extra plus. They easily add 20% additional vote which tips the balance.
And it is not just that these people benefitted from the schemes. The BJP kaaryakarta goes to the village to make sure that they know who gave them the benefits. The Karyakarta knows that his hard work will be rewarded. Modi was a grassroot level worker whose organization skills were recognized by the Party and he was asked to helm Gujarat after the 2001 earthquake. He transformed Bhuj from a sleepy desert town to a bustling metropolis. He transformed Kutch from a desert to a tourist destination with the Rann Utsav and now lakhs of people come there every year to breathe the "Khushboo Gujarat Ki" (Amitabh Bachchan) He brought the Narmada waters to the farthest villages of Gujarat all the while busybodies like that Medha Patkar tried to stop the development.
An Amit Shah started his career putting posters for the BJP and now he is the 2nd most powerful man in the government.
The TV and flags you see in the picture would have been put by a nameless (to us) Karyakarta but he would be known in the village and after Amit Shah's speech he would have explained everything the government is doing. The people in the photo may not have understood Hindi, so he would have translated the words to Bengali.
@Bilal9 would laugh at just 3 people but it is not just 3. In thousands of villages across Bengal this would have been repeated. A congress, TMC or CPI(M) is not doing any of this. And the best part, elections are more than an year away but BJP is already campaigning. Amit Shah has set his eyes on Kolkata and he would do whatever it takes to install his government in Writer's Building.
@jamahir you know one more funny thing, the person who installed that TV and flag may even be an ex CPI(M) guy