Please help me to understand one more sentence...

[Angie8]

I'm trying to translate the paragraph below into Chinese, but there's one sentence confused me: "because their media advisers certainly do."
What the advisers do? What the word "do" here means? (Sorry if my question is unclear...I just simply don't understand what this sentence mean in this paragraph)

"A former Fleet Street editor commented on Sánchez Junco’s ‘froth of life’ achievement worldwide: ‘Gossip was therefore transformed from a whisper over the garden wall … into a scream for attention on the spot-lit drawing room sofa’ (Daily Telegraph, 15 July 2010). The sociologist Professor Stuart Hall puts it differently. Hall calls such stories a ‘personalising transformation’ for the celebrity or politician involved, making us think better, or at least differently, about them. Imagine, therefore, because their media advisers certainly do, a world in which presidents of the United States, prime ministers of Great Britain or Japan, chancellors of Germany and chief executives of multinational corporations like BP and Microsoft can avoid the inbuilt hostility and negativity of the White House press corps, the international press commentariat and those despicably cocky interviewers on the BBC."

[5jj]

The media advisers imagine a world in which presidents of the United States, prime ministers of Great Britain or Japan, chancellors of Germany and chief executives of multinational corporations like BP and Microsoft can avoid the inbuilt hostility and negativity of the White House press corps, the international press commentariat and those despicably cocky interviewers on the BBC.

[billmcd]

I'm trying to translate the paragraph below into Chinese, but there's one sentence confused me: "because their media advisers certainly do."
What the advisers do? What the word "do" here means? (Sorry if my question is unclear...I just simply don't understand what this sentence mean in this paragraph)

"A former Fleet Street editor commented on Sánchez Junco’s ‘froth of life’ achievement worldwide: ‘Gossip was therefore transformed from a whisper over the garden wall … into a scream for attention on the spot-lit drawing room sofa’ (Daily Telegraph, 15 July 2010). The sociologist Professor Stuart Hall puts it differently. Hall calls such stories a ‘personalising transformation’ for the celebrity or politician involved, making us think better, or at least differently, about them. Imagine, therefore, because their media advisers certainly do, a world in which presidents of the United States, prime ministers of Great Britain or Japan, chancellors of Germany and chief executives of multinational corporations like BP and Microsoft can avoid the inbuilt hostility and negativity of the White House press corps, the international press commentariat and those despicably cocky interviewers on the BBC."

The media advisers certainly imagine (they do = they imagine) a world etc., etc.