Meaning of "at an arm's length"

Solution 1:

The answer seems clear at an arm's length,

= at a relatively close distance; on cursory examination.

This is to be distinguished from

(OED)

(i) P2d (a) at arm's length. (idiom)

(i) As far as one can reach with one's arm; (hence) at a distance, remote, not on familiar or friendly terms.

1655 W. Gurnall Christian in Armour: 1st Pt. 68 He hath his weapon in his hand, with which he will keep the Preacher, and the Word he chargeth him with at armes length.

1999 J. Burchill Married Alive iv. 58 Your neighbours are easy enough to keep at arms length.

and

(ii) arm's-length adj. Conducted or agreed by independent parties not able to coerce or control each other; characterized by distance, independence, or impartiality.

1920 Jrnl. Polit. Econ. 28 241 A process of arm's-length bargaining.

2014 Real Estate Taxation 42 No. 1 26/2 If there are any transactions between the companies..they must be on an arm's-length basis.

and, of course, the literal meaning:

2020 Greybeard EL&U "She held the bucket at arm's length."

Solution 2:

I have never seen "at arm's length" used in this context, but would understand the author to mean "at first glance". Keeping something or someone "at arm's length" normally means that you are deliberately avoiding close contact or intimacy.