English: Photo of historical Community of Christ seal from Nauvoo, Illinois.

Per Community of Christ 1917 General Conference Resolution 163, its the-lamb-&-the-lion seal was altered thus:

"[…I]nsert, 'a child' after emblem and cross out 'lying down at rest' following the word 'lamb.' 'Third line same paragraph insert 'and 1891' after 'Incorporated 1872." (March 29, 1947 Saints Herald, v. 94 p. 260). Citation: http://www.ijmsonline.org/archives/3342

Hence as early 1917 iterations similar to this brass/bronze plaque were posted on the denomination's various churches and buildings, their seals featuring the motto "PEACE" with pictorial relief of the Peaceable Kingdom--viz., a child, the lamb, and the lion together without ire--and with script around its circumference bearing the then name of the denomination: "REORGANIZED CHURCH OF JESUS CHRIST OF LATTER DAY SAINTS". Note that this exact iteration of the seal however dates from the 1950s as it has braiding around the outside (removed in the 1960s) and two olive branches at its bottom (in the 1960s: simplified to one olive branch).

According to denomination historian John Hamer, "Since the late 19th century, the [Community of Christ] church seal has been a picture of the lamb, lion, and child emblazoned with the motto 'Peace.'" https://saintsherald.com/2013/11/29/how-blessed-the-day-when-the-lamb-and-the-lion/

Indeed, the seal approved in 1874 by the Community of Christ's General Conference had contained the lion and lamb and a child:

"[...] During the Tuesday morning session on April 7 Joseph III gave his report on the Australasia mission,⁷ The next day the Committee on Church Seal of Joseph III, Jason W, Briggs, and Elijah Banta offered their design with the lion, the lamb, and child as the prominent figures. The committee inserted the term "PEACE" cradled in two olive branches at the bottom of the seal. But it is likely that the great success of Rodger and Wandell in Tahiti prompted the insertion of the palm tree in the background.^{8 [...footnotes] 7. 'Minutes of the Annual Conference of April 6, 1874'   8. For a discussion of this see Lawrence W. Tyree," Impressions with a Purpose: Omissions, Myths, and the Real Origins of the Church Seal," Restoration Studies : Theology and Culture in the Community of Christ and the Latter Day Saint Movement 12 (2011)"} -- [Mark A. Scherer (2012). "The Future of the Past Under the Southern Cross". The John Whitmer Historical Association Journal 32 (2): 188-96.]

Its iconographic representation of peace is derived from Isaiah 11:6,7: "The wolf will live with the lamb, the leopard will lie down with the goat, the calf and the lion and the yearling together; and a little child will lead them. The cow will feed with the bear, their young will lie down together, and the lion will eat straw like the ox."

Community of Christ Sings! (Independence, MO: Herald Publishing House. 2013) #384: "The Spirit of God Like a Fire is Burning" (verse 3):

“How blessed the day when the lamb and the lion / shall lie down together in peace with a child.
 With one heart and mind may the Lord call us Zion: / a people of justice, by God’s love inspired.”

(Cf.: Commons.Wikimedia.org/wiki/File:William Strutt Peace 1896. Furthermore, in heraldry, the lamb often represents "Christ"; the lion, "the Resurrection. (Cf.: "He endured death as a lamb; he devoured it as a lion." – Augustine, Sermon 375A.) For Canadian registration of this heraldry, see here: http://reg.gg.ca/heraldry/pub-reg/project-pic.asp?lang=e&ProjectID=487&ProjectElementID=1639 :

"Blazon
"Arms: Purpure a child statant affronty proper crined Or habited in a tunic Argent belted Or between a lion couchant guardant Or and a lamb statant Argent. Motto: PEACE."
 -- from Canadian heraldry registration for Community of Christ

)