There are traditions in our hadith books according to which angels do not enter houses where portraits of animate beings are kept. It is necessary to mention a few points in regards to such traditions:
A) The word "portrait" in the traditions includes pictures as well as statues of animate beings.
B) Most of these traditions are weak and inauthentic (without a trustworthy chain of transmission).
C) Religious authorities have mentioned these tradition in respect of those places where offering prayers is makrooh (abominable).
It is for the same reason that the jurists have said: Offering prayers is makrooh (abominable) at certain places including "facing the picture or statue of living creatures, unless it is covered. It is makrooh to offer prayers at a place where there is a picture, even if it may not be placed in front of the person who offers prayers". Therefore, offering prayers at a place where there is the image of human and animate beings is abominable irrespective of whether the picture is in a mosque or elsewhere or whether it is in front of the people offering prayers or behind them. If there is a picture, it is better to cover the picture with something during prayers.
In any case, according to the verdict of most of the current jurists, there is no objection in hanging up and keeping portraits, statues and (inoffensive) pictures in houses, public places and squares.
 - Kulayni, Muhammad bin Ya'qub, Al-Kafi, vol.6, pg.528, hadith 13, Islamic Publications, Tehran 1407 A.H.; Al-Tahzib, Muhammad bin Hasan Tusi, vo.2, pg.377, hadith 102, Islamic Publications, Tehran 1407 A.H.
 - Majlisi, Mer'atul Uqul fi Sharh Akhbar Aal Al-Rasul, Muhammad Baqir Majlisi, vol.15, pg.299, Islamic Publications, Tehran, 1404 A.H.
 - Ibid.
 - Muntahal Matlab fi Tahqiq al-Mazhab, Hilli, Hasan bin Yusuf, vol.4, pg.324, Majma' al-Bohuth al-Islamiyah, Mashad, 1412 A.H.
 - Tauzihul Masail of Imam Khomeini (with connotation), vol.1, issue No.898.
 - Answer partially extracted from answer 855 (site:930).
 - Current Legal Issues according to the verdicts of Grand Scholars, Sayyid Mohsen Mahmoodi, Sahib al-Zaman Publications, pg.43, (extracted from Porsman software).