A detailed numerical study of electronic transmittance has been carried out to analyse the nature of the metallic behaviour around the dimer site energy. The transmittance versus energy curve exhibits resonance features, i.e. it becomes nearly flat at and around the dimer on-site energy apart from showing other transmission resonances. The spatial variation of the transmittance for energies in the vicinity of the dimer on-site energy shows Bloch-like extended character. For electron energies slightly away from this region, the transmittance shows some oscillation with energy, and the transmission resonances show spatial variation, having fragmented character which may be attributed to the deviation from the typical Bloch-like extended character of the states in the vicinity of the dimer on-site energy. Our multifractal scaling analysis for the normalized transmittance distinguishes the resonances in the two different regimes.